Identify which type of sampling is used: random, stratified, cluster, systematic, or convenience.



1. A psychologist selects 12 boys and 12 girls from each of four Science classes.

2. When he made an important announcement, he based his conclusion on 10 000 responses, from
100 000 questionnaires distributed to students.

3. A biologist surveys all students from each of 15 randomly selected classes.

4. The game show organizer writes the name of each contestant on a separate card, shuffles the cards, and
draws five names.

5. Family Planning polls 1 000 men and 1 000 women about their views concerning the use of contraceptives.

6. A hospital researcher interviews all diabetic patients in each of ten randomly selected hospitals. ​

Answers

Answer 1

1. A psychologist selects 12 boys and 12 girls from each of four Science classes. = Stratified sampling

2. When he made an important announcement, he based his conclusion on 10 000 responses, from 100 000 questionnaires distributed to students= Convenience sampling

3. A biologist surveys all students from each of 15 randomly selected classes = Cluster sampling

4. The game show organizer writes the name of each contestant on a separate card, shuffles the cards, and draws five names= Random sampling

5. Family Planning polls 1 000 men and 1 000 women about their views concerning the use of contraceptives= Stratified sampling

6. A hospital researcher interviews all diabetic patients in each of ten randomly selected hospitals = Cluster sampling

To know more about "Stratified sampling" refer here:

https://brainly.com/question/2054469#

#SPJ11


Related Questions

Line x is parallel to line y. Line z intersect lines x and y. Determine whether each statement is Always True

Answers

a and b are always true

The box plot displays the number of push-ups completed by 9 students in a PE class.

A box plot uses a number line from 12 to 58 with tick marks every 2 units. The box extends from 27.5 to 42.5 on the number line. A line in the box is at 37. The lines outside the box end at 15 and 55. The graph is titled Push-Ups In PE and the line is labeled Number of Push-Ups.

Which of the following represents the value of the lower quartile of the data?

27.5
37
42.5
55

Answers

the answer is Q1 = 27.5

In 1990, when the consumer price index (CPI) was 130.7, Deena purchased a
house for $98,700. Assuming that the price of houses increased at the same
rate as the CPI from 1980 to 1990, approximately how much would the house
have cost in 1980, when the CPI was 82.4?
OA. $72,650
OB. $67,600
O C. $62,200
OD. $84,600

Answers

Answer:

C is the right answer I think

Final answer:

To find the cost of the house in 1980, divide the cost of the house in 1990 by the rate of increase. The house would have cost approximately $62,200 in 1980 when the CPI was 82.4.

Explanation:

To find the cost of the house in 1980, we need to use the concept of inflation. In this case, we can use the consumer price index (CPI) to compare the prices of the house in 1990 and 1980.

First, we need to determine the rate of increase from 1980 to 1990. The rate of increase is calculated by dividing the CPI in 1990 by the CPI in 1980:

Rate of increase = CPI in 1990 / CPI in 1980 = 130.7 / 82.4 = 1.585

Next, we can use the rate of increase to find the cost of the house in 1980. We divide the cost of the house in 1990 by the rate of increase:

Cost in 1980 = Cost in 1990 / Rate of increase = $98,700 / 1.585 = $62,200.

Therefore, the house would have cost approximately $62,200 in 1980 when the CPI was 82.4.

Learn more about Consumer Price Index (CPI) here:

https://brainly.com/question/32748102

#SPJ3

Write the product 5x2/3 as the product of a whole number and a unit fraction

Answers

The product 5x^(2/3) can be written as the product of the whole number 5 and the unit fraction 1/x^(-2/3), which simplifies to x^(2/3)/1 or just x^(2/3). So, we have:

5x^(2/3) = 5 * (1/x^(-2/3)) = 5x^(2/3) = 5 * (x^(2/3) / 1) = 5x^(2/3) = 5x^(2/3)

To write the product 5x^(2/3) as the product of a whole number and a unit fraction, we need to express x^(2/3) as a unit fraction.

Recall that a unit fraction is a fraction with a numerator of 1, so we need to find a fraction that has 1 as the numerator and x^(2/3) as the denominator. We can do this by using the reciprocal property of exponents:

x^(2/3) = 1 / x^(-2/3)

Now we can substitute this expression into the original product:

5x^(2/3) = 5 * (1 / x^(-2/3))

Simplifying the right-hand side of the equation, we can write it as:

5 / x^(-2/3) = 5x^(2/3)

To know more about unit fraction refer to

https://brainly.com/question/30860953

#SPJ11

Which of these could be the side lengths of a right triangle? list all possible answers and show your work for full marks.

a) 4-7-10
b) 36-48-60
c) 6-10-14
d) 14-48-50

Answers

The sets of side lengths that could form a right triangle are 36-48-60 (option b) and 14-48-50 (option d).

To determine which of these sets of side lengths could form a right triangle, we will use the Pythagorean theorem (a² + b² = c²), where a and b are the shorter sides and c is the hypotenuse. Let's evaluate each option:

a) 4-7-10
Applying the Pythagorean theorem: 4² + 7² = 16 + 49 = 65, which is not equal to 10² (100). So, this set does not form a right triangle.

b) 36-48-60
Applying the Pythagorean theorem: 36² + 48² = 1296 + 2304 = 3600, which is equal to 60² (3600). So, this set does form a right triangle.

c) 6-10-14
Applying the Pythagorean theorem: 6² + 10² = 36 + 100 = 136, which is not equal to 14² (196). So, this set does not form a right triangle.

d) 14-48-50
Applying the Pythagorean theorem: 14² + 48² = 196 + 2304 = 2500, which is equal to 50² (2500). So, this set does form a right triangle.

In conclusion, the sets of side lengths that could form a right triangle are 36-48-60 (option b) and 14-48-50 (option d).

To know more about " Pythagorean theorem" refer here:

https://brainly.com/question/14930619#

#SPJ11

Ed


8. A watering can holds 3 liters of water.


If Patricia waters her vegetable garden


5 times a day and uses one full can in


all, how many milliliters of water does


she use each time she waters?


~ 60 mL


B 3,000 mL


© 600 mL


D 300 ml


SNO


9. Find 4-5.

Answers

8. Patricia uses 600 milliliters of water each time she waters her vegetable garden. The correct option is A © 600 mL.

9. 4-5 =-1

For first question:

8. A watering can holds 3 liters of water, and Patricia waters her vegetable garden 5 times a day using one full can in total. To find out how many milliliters of water she uses each time, you need to first convert the 3 liters to milliliters (1 liter = 1,000 milliliters) and then divide by 5.

3 liters × 1,000 milliliters/liter = 3,000 milliliters
3,000 milliliters ÷ 5 = 600 milliliters

So, Patricia uses 600 milliliters of water each time she waters her vegetable garden. The correct answer is 600 mL.

9. For second question, the calculation is as follows:

4 - 5 = -1

To know more about amount of water, refer to the link below:

https://brainly.com/question/23170599#

#SPJ11

for each of the following situations identify the relation as linear quadratic or exponential. a. Larry is paid $10 per hour he receives a $1 per hour raise each year

Answers

The problem represents a linear equation.

What is linear equation?

A linear equation is a particular type of equation in which the highest power of the variable is always 1(linear). This type of equation is also known as a one-degree equation.

Larry is paid $10 per hour he receives a $1 per hour raise each year.

Let he works for x hours.

In 1 hour he receives $10 so for x hours he will receive $10x

$1 per hour raise.

So there will be a linear equation

The linear equation will be if we take total income as $y then,

y= 10x+1

which is of the linear equation form y=m x+ b where m is the slope.

Hence, the problem represents a linear equation.

To know more about linear equation

https://brainly.com/question/12788590  from the link.

#SPJ9

What is constant of proportionality if y=1. 75x

Answers

The constant of proportionality is 1.75.

What is proportion?

A percentage is created when two ratios are equal to one another. We write proportions to construct equivalent ratios and to resolve unclear values. a comparison of two integers and their proportions. According to the law of proportion, two sets of given numbers are said to be directly proportional to one another if they grow or shrink in the same ratio.

Given two variables x and y, y is directly proportional to x (x and y vary directly, or x and y are in direct variation) if there is a non-zero constant k such that

=> y=kx

The relation is often denoted, using the ∝ or ~ symbol, as

=> y ∝ x

and the constant ratio

=> k =y/x

In this equation y=1.75 x.

Hence the constant of proportionality is 1.75.

To learn more about proportion refer the below link

https://brainly.com/question/13604758

#SPJ4

A lawn sprinkler sprays water 2.5 meters in every direction as it rotates. What is the area of the sprinkled lawn?

Answers

The area of the sprinkled lawn is approximately 19.625 square meters.

What is the area of the sprinkled lawn?

The formula for the area of a circle is:

A = πr²

Where A is the area and r is the radius and π is constant pi ( 3.14 ).

If the sprinkler as a circle with a radius of 2.5 meters. The area that the sprinkler can cover is the area of this circle.

Here, the radius is 2.5 meters, so we can substitute that into the formula:

A = πr²

A = 3.14 × 2.5²

Area = 3.14 × 6.25

Area = 19.625 m²

Therefore, the area is 19.625 m²

Learn more about circles here:https://brainly.com/question/20693416

#SPJ1

PLEASE HELP ME WITH THIS MATH PROBLEM!!! WILL GIVE BRAINLIEST!!! 25 POINTS!!!

Answers

Answer:  In bold

Step-by-step explanation:

The formula they gave is a rate

Let's solve for the rate first.

This equation is done for 3 years 2018-2021  that's why ^3

3.55 =  2.90(1+x)³                 >divide both sides by 2.90

1.224 = (1+x)³                         > take cube root of both sides

1.0697 =  1+x

x= .0697

so let's make our generic formula

[tex]y = 2.90(1+.0697)^{t}[/tex]        let t be years and let y=  price  

Let's calculate 2018, so this would be year 0

[tex]y = 2.90(1+.0697)^{0}[/tex]

y=$2.90   this is for 2018

They already gave you 2021 price

y=$3.55   this is for 2021

Rate of increase is .0697 

In 2025

That's 7 years=t

[tex]y = 2.90(1+.0697)^{7}[/tex]

y=$4.65    for 2025

A, b & c form the vertices of a triangle.
∠cab = 90°,
∠abc = 65° and ac = 8.9.
calculate the length of bc rounded to 3 sf.

Answers

The length of BC rounded to 3 significant figures is 6.98.

Since ∠cab = 90°, we can use the Pythagorean Theorem to find the length of AB.

Let's call BC = x, then we have:

sin(65°) = AB/BC

AB = sin(65°) * BC

In right triangle ABC, we have:

AB^2 + BC^2 = AC^2

(sin(65°) * BC)^2 + BC^2 = 8.9^2

Solving for BC, we get:

BC = 8.9 / sqrt(sin^2(65°) + 1)

BC ≈ 6.98

Therefore, the length of BC rounded to 3 significant figures is 6.98.

To know more about length, visit:

https://brainly.com/question/9842733#

#SPJ11

Mathematical
PRACTICE
Use Algebra For Exercises 11-13,
2 x P
40
refer to the equation 5 x 9
100
2
11. What must be true about p and q if the equation show
equivalent fractions?

Answers

p and q both are equal and p=q=20.

Given are an equation show equivalent fractions 2p/5q = 40/100

We need to find the p and q,

So

2p/5q = 40/100

2p/5q = 2×20/2×20

p/q = 20/20

p/q = 1

p = q

Therefore p and q both are equal and p=q=20.

Learn more about equivalent fraction click;

https://brainly.com/question/29766013

#SPJ1

Karmen is buying a new car. For the car's exterior, she can choose from three colors-black, gray, or white. For the interior, she can choose between


belge and gray. She can also choose between a manual and an automatic transmission


if Karmen picks a car at random, what is the probability of picking a car that has a black exterior and a belge interior?


What is the probability of picking a car with a belge interior and an automatic transmission?


The probability of Karmen picking a car with a black exterior and a belge interior is


The probability of Karmen picking a car with a belge interior and an automatic transmission is

Answers

The probability of Karmen picking a car with a belge interior and an automatic transmission is 1/6

How to find the probability?

To find the probability, we need to start by identifying the event or situation for which we want to calculate the probability.

Since Karmen has three choices for the exterior color, two choices for the interior color, and two choices for the transmission, the total number of possible car configurations is:

3 x 2 x 2 = 12

This means there are 12 different cars to choose from.

To find the probability of picking a car that has a black exterior and a belge interior, we need to determine how many cars meet these criteria. There is only one car that has a black exterior and a belge interior, so the probability of picking this car is:

1/12

Therefore, the probability of Karmen picking a car with a black exterior and a belge interior is 1/12.

To find the probability of picking a car with a belge interior and an automatic transmission, we need to determine how many cars meet these criteria. There are two cars that have a belge interior and an automatic transmission, so the probability of picking one of these cars is:

2/12

Simplifying this fraction gives:

1/6

Therefore, the probability of Karmen picking a car with a belge interior and an automatic transmission is 1/6.

Learn more about probability

brainly.com/question/11234923

#SPJ11

During their team meeting, both managers shared their findings. Complete the statement describing their combined results.



Select the correct answer from each drop-down menu.



The initial number of video views was ____ the initial number of site visits, and the number of video views grew by _____ the number of site visits.



The difference between the total number of site visits and the video views after 5 weeks is _____.



More than


the same as


fewer than



a smaller factor than


the same factor as


a larger factor than



20,825


52,075


15,625


36,450

Answers

The initial number of video views was fewer than the initial number of site visits, and the number of video views grew by a larger factor than the number of site visits. The difference between the total number of site visits and the video views after 5 weeks is 20,825.

During their team meeting, both managers shared their findings. Complete the statement describing their combined results.

The initial number of video views was fewer than the initial number of site visits, and the number of video views grew by a larger factor than the number of site visits.

The difference between the total number of site visits and the video views after 5 weeks is 20,825.

Therefore the correct answer are fewer, larger factor than and 20,825.

Read more about video.

https://brainly.com/question/15245269

#SPJ11

Morris shovels driveways during a big snowstorm. He charges $25 to shovel a drive way. He can shovel a drive way in a half hour assuming that he worked back to back how much could he make in 5 hours

Answers

Answer:

250

Step-by-step explanation:

5 x 2= 10

25 x 10= 250

If Mikal uses all his money to buy one type of flour, he has exactly enough money to buy either 12 pounds of wheat flour, or 6 pounds of rice flour, or 4 pounds of almond flour. If Mikal uses all his money to buy an equal number of pounds of all three types of flour, what is the total number of pounds of flour that he can buy?

Answers

The total number of pounds of flour he can buy is 7 pounds of flour

Let's assume that Mikal has $1 to spend on flour. According to the problem, he can buy:

- 12 pounds of wheat flour for $1, which means that the price of wheat flour is 1/12 = $0.0833 per pound.

- 6 pounds of rice flour for $1, which means that the price of rice flour is 1/6 = $0.1667 per pound.

- 4 pounds of almond flour for $1, which means that the price of almond flour is 1/4 = $0.25 per pound.

If Mikal spends $1 on an equal amount of all three types of flour, he will spend $1/3 = $0.3333 on each type of flour. To determine how many pounds of each type of flour he can buy, we need to divide $0.3333 by the respective price per pound of each type of flour:

- Wheat flour: $0.3333 / $0.0833 per pound = 3.9996 pounds (rounded to 4 pounds)

- Rice flour: $0.3333 / $0.1667 per pound = 1.9998 pounds (rounded to 2 pounds)

- Almond flour: $0.3333 / $0.25 per pound = 1.3332 pounds (rounded to 1 pound)

Therefore, Mikal can buy 4 pounds of wheat flour, 2 pounds of rice flour, and 1 pound of almond flour with $1. The total number of pounds of flour he can buy is:

4 + 2 + 1 = 7 pounds of flour.

To know more about pounds, visit:

https://brainly.com/question/29181271#

#SPJ11

To the nearest cubic​ centimeter, what is the volume of the regular hexagonal​ prism?

a hexagonal prism has a height of 7 centimeters and a base with a side length of 3 centimeters. a line segment of length 2.6 centimeters connects a point at the center of the base to the midpoint of one of its sides, forming a right angle.


the volume of the regular hexagonal prism is about ___ cm3

Answers

Rounded to the nearest cubic centimeter, the volume of the regular hexagonal prism is approximately 82 [tex]cm^3.[/tex]

To calculate the volume of the regular hexagonal prism, we need to find the area of the base and multiply it by the height.

The base of the prism is a regular hexagon with side length 3 centimeters. The formula for the area of a regular hexagon is:

[tex]Area = (3√3/2) * (side length)^2.[/tex]

Substituting the given side length of 3 centimeters:

[tex]Area = (3√3/2) * 3^2[/tex]

= (3√3/2) * 9

= (27√3/2).

Now, let's calculate the volume by multiplying the base area by the height:

Volume = Area * height

= (27√3/2) * 7

≈ 81.729[tex]cm^3[/tex].

To know more about regular hexagonal prism, refer here:

https://brainly.com/question/23646357

#SPJ11

A study reports that in 20102010 the population of the United States was 308,745,538308,745,538 people and the land area was approximately 3,531,9053,531,905 square miles. ​Based on the study, what was the population density, in people per square mile, of the United States in 20102010? ​Round your answer to the nearest tenth. ​

Answers

The population density is 87.4, under the condition that a study report shows that in 2010 the population of the United States was counted to be  308,745,538 people and the land area is approximately 3,531,905 square miles.

Now to evaluate  the population density of the United States in 2010, here we have to use the principles of division
Population density = Population / Land area

Staging  the values from the study
Population density = 308,745,538 / 3,531,905
The evaluated Population density = 87.4 people per square mile

Then, the United State's population density in 2010 was  evaluated as 87.4 people per square mile.

To learn more about population density
https://brainly.com/question/13902749
#SPJ4
The complete question is
A study reports that in 2010 the population of the United States was 308,745,538 people and the land area was approximately 3,531,905 square miles. ​Based on the study, what was the population density, in people per square mile, of the United States in 2010? ​Round your answer to the nearest tenth. ​

3. The insurance company also offers safety glass coverage. There is a 50% chance of no repairs ($0), a 30% chance of minor repairs ($50), and a 20% chance of full replacement ($300). Which plan for optional safety glass coverage has the lower expected cost?

Enter your answer.

Answers

Plan C has the lower expected cost, so, this is best to minimize costs for safety glass coverage.

How can we compare the plans?

In order to compare expected cost of Plan C and D, we must calculate expected payout for each plan and add to the premium.

For Plan C, expected payout is:

= 0.5*(0) + 0.3*(50) + 0.2*(300)

= 15 + 60

= 75

The total expected cost of Plan C is:

= 75 + 50 + 20

= 145

For Plan D, expected payout is:

= 0.5*(0) + 0.3*(50) + 0.2*(300)

= 15 + 60

= 75

The total expected cost of Plan D is:

= 75 + 100 + 0

= 175

Therefore, the Plan C has the lower expected cost.

Read more about glass coverage

brainly.com/question/30557791

#SPJ1

Rotate the vector (0,2) 270°


clockwise about the origin.

Answers

The rotated vector is (-2,0). To see why, imagine the original vector (0,2) plotted on the coordinate plane. To rotate it 270° clockwise about the origin, we can first rotate it 90° clockwise to get (2,0), then rotate that 180° clockwise to get (-2,0).

To understand this geometrically, think of the vector (0,2) as pointing straight up on the y-axis. Rotating it 90° clockwise means it now points to the right on the x-axis. Then, rotating it another 180° clockwise means it points straight down on the negative y-axis, which corresponds to the vector (-2,0).

In general, to rotate a vector (x,y) by an angle θ about the origin, we can use the following formulas: x' = x cos θ - y sin θ. y' = x sin θ + y cos θ In this case, θ = 270°, so cos θ = 0 and sin θ = -1.

Plugging in x=0, y=2, we get: x' = 0 - 2(-1) = 2 y' = 0(270) + 2(0) = 0. So the rotated vector is (2,0), which corresponds to (-2,0) because we rotated it clockwise instead of counterclockwise.

Learn more about vector here:

https://brainly.com/question/24256726

#SPJ4

Suppose that the future price p(t) of a certain item is given by the following exponential function. In this function, p(t) is measured in dollars and r is the


number of years from today.


pt) = 2000(1. 039)'


QD


Find the initial price of the item.


SU


Does the function represent growth or decay?


O growth O decay


By what percent does the price change each year?

Answers

The price of the item increases by approximately 3.93% each year.

Find out what is the initial price of the item and what percentage of the price changes each year?

The initial price of the item is the value of p(0), which can be obtained by setting r=0 in the given function. Therefore:

p(0) = 2000(1.039)^0 = 2000

So the initial price of the item is $2000.

To determine whether the function represents growth or decay, we need to look at the value of the base of the exponential function, which is 1.039 in this case. Since this value is greater than 1, the function represents growth.

To find the percentage change in price each year, we can calculate the percentage increase from the initial price to the price after one year (r=1):

p(1) = 2000(1.039)^1 = 2078.60

The percentage increase from $2000 to $2078.60 is:

((2078.60 - 2000)/2000) x 100% ≈ 3.93%

Therefore, the price of the item increases by approximately 3.93% each year.

Learn more about Percentage.

brainly.com/question/14267101

#SPJ11

Terri is beginning a science experiment in the lab. The instructions call for 227 milligrams of potassium. Calculate the difference between this amount and 1 gram

Answers

The difference between the amount of potassium called for in the experiment (0.227 grams) and 1 gram is 0.773 grams.

The amount of potassium called for in the experiment is 227 milligrams. To convert milligrams to grams, we divide by 1000: 227/1000 = 0.227 grams.

The amount of 1 gram is larger than 0.227 grams. To find the difference between the two amounts, we subtract the smaller amount from the larger amount:

1 gram - 0.227 grams = 0.773 grams

Therefore, the difference between the amount of potassium called for in the experiment (0.227 grams) and 1 gram is 0.773 grams.

Learn more about "difference ":

https://brainly.com/question/17695139

#SPJ11

The radioactive substance uranium-240 has a half-life of 14 hours. The amount At) of a sample of uranium-240 remaining (in grams) after thours is given by


the following exponential.


A (t) = 5600


100(3)*


Find the amount of the sample remaining after 11 hours and after 50 hours.


Round your answers to the nearest gram as necessary.


Amount after 11 hours: grams


Amount after 50 hours: grams

Answers

Amount after 11 hours: 3,477,373 grams; Amount after 50 hours: 33,320 grams.

How to find the Radioactive decay ?

The Radioactive decay formula provided in the question for the amount A(t) of a sample of uranium-240 remaining after t hours is:

A(t) = 5600100(3[tex])^(-11/14)[/tex]

To find the amount of the sample remaining after 11 hours, we substitute t = 11 in the formula and calculate:

A(11) = 5600100(3[tex])^(-11/14)[/tex] ≈ 3477373 grams

Therefore, the amount of the sample remaining after 11 hours is approximately 3,477,373 grams (rounded to the nearest gram).

Similarly, to find the amount of the sample remaining after 50 hours, we substitute t = 50 in the formula and calculate:

A(50) = 5600100(3[tex])^(-50/14)[/tex] ≈ 33320 grams

Therefore, the amount of the sample remaining after 50 hours is approximately 33,320 grams (rounded to the nearest gram).

The exponential formula for radioactive decay describes the behavior of a radioactive substance, where the amount of the substance decreases over time as it decays. In this case, uranium-240 has a half-life of 14 hours, which means that half of the initial amount of the substance will decay in 14 hours. After another 14 hours, half of the remaining amount will decay, and so on.

As time goes on, the amount of uranium-240 remaining decreases exponentially, and the rate of decay is determined by the half-life of the substance. The formula provided in the question allows us to calculate the amount of uranium-240 remaining after any given amount of time, based on its initial amount and half-life.

Learn more about Radioactive decay

brainly.com/question/1770619

#SPJ11

The radioactive substance uranium-240 has a half-life of 14 hours.  The amount of the sample remaining after 11 hours is approximately 2265 grams, and the amount of the sample remaining after 50 hours is approximately 95 grams.

The formula for the amount of uranium-240 remaining after t hours is given by: A(t) = 5600 * (1/2)^(t/14).
Find the amount of the sample remaining after 11 hours, we substitute t = 11 into the formula and evaluate:
A(11) = 5600 * (1/2)^(11/14)
A(11) ≈ 2265 grams (rounded to the nearest gram)
Find the amount of the sample remaining after 50 hours, we substitute t = 50 into the formula and evaluate:
A(50) = 5600 * (1/2)^(50/14)
A(50) ≈ 95 grams (rounded to the nearest gram)
Therefore, the amount of the sample remaining after 11 hours is approximately 2265 grams, and the amount of the sample remaining after 50 hours is approximately 95 grams.

Read more about Radioactive substance.

https://brainly.com/question/1160651

#SPJ11

Write the equation in factored form:

so x= what values?

What do the solutions for x mean?

x2−4x−21=0

Answers

x2 - 4x -21=0
For factorising first split the middle
term - 4x as - 7x and + 3x as -7x + 3x
- 4x and (-7x) (3x) = - 21 x2
=×2-7× +3x -21=0
= x (x-7) + 3(x -7) = 0
= (x + 3) (x - 7) = 0
Hence. the factors of x2 - 4x - 21 =
O are (x + 3) and (x - 7).

A car drives down a road in such a way that its velocity ( in m/s) at time t (seconds) is v(t) =1t^(1/2) + 4 Find the car's average velocity in (m/s) between t=4 and t=10.Â

Answers

To find the car's average velocity between t=4 and t=10, we need to use the formula:

average velocity = (change in displacement) / (change in time)

Since we are only given the velocity function, we need to first find the displacement function by integrating the velocity function:

displacement = ∫(1t^(1/2) + 4) dt

displacement = (2/3)t^(3/2) + 4t + C

where C is the constant of integration.

Since we are only interested in the change in displacement between t=4 and t=10, we can ignore the constant of integration.

change in displacement = [(2/3)10^(3/2) + 4(10)] - [(2/3)4^(3/2) + 4(4)]

change in displacement = 28.147 - 14.265

change in displacement = 13.882

Now we can use the formula for average velocity:

average velocity = (change in displacement) / (change in time)

average velocity = 13.882 / (10 - 4)

average velocity = 1.98 m/s

Therefore, the car's average velocity between t=4 and t=10 is 1.98 m/s.

Learn more about average velocity,

https://brainly.com/question/24824545

#SPJ11

Calculate A. ∂z and ∂x
B. ∂z and ∂y
at the point
(5, 17, 1)
where z is defined implicitly by the equation
z4 + z2x2 − y − 9 = 0

Answers

At the point (5, 17, 1), the partial derivatives of z with respect to x and y are -12.5 and 0.25, respectively, as calculated using implicit differentiation. At the point (5, 17, 1), the partial derivatives of z with respect to z and y are 0.16 and -1.

To find the partial derivatives, we need to use the implicit differentiation.

To find ∂z/∂x, we differentiate the equation with respect to x, treating y and z as functions of x

4z^3(dz/dx) + 2z^2x^2 - 0 - 0 = 0

Simplifying, we get

4z^3(dz/dx) = -2z^2x^2

(dz/dx) = -1/2x^2z

At the point (5, 17, 1), we have

(dz/dx) = -1/2(5)^2(1) = -12.5

To find ∂z/∂y, we differentiate the equation with respect to y, treating x and z as functions of y

4z^3(dz/dy) - 1 - 0 + 0 = 0

Simplifying, we get

4z^3(dz/dy) = 1

(dz/dy) = 1/4z^3

At the point (5, 17, 1), we have

(dz/dy) = 1/4(1)^3 = 0.25

To find ∂z and ∂y at the point (5, 17, 1), we need to take partial derivatives with respect to z and y, respectively, of the implicit equation

z^4 + z^2x^2 - y - 9 = 0

Taking the partial derivative with respect to z, we get

4z^3 + 2z^2x^2(dz/dz) - dy/dz = 0

Simplifying and solving for ∂z, we get

∂z = dy/dz = 8z^3/(2z^2x^2) = 4z/x^2

At the point (5, 17, 1), we have

z = 1, x = 5

So, ∂z at the point (5, 17, 1) is

∂z = 4z/x^2 = 4(1)/(5^2) = 0.16

To find ∂y, we take the partial derivative with respect to y, keeping x and z constant

-1 = ∂y

Therefore, ∂y at the point (5, 17, 1) is -1.

To know more about partial derivatives:

https://brainly.com/question/31397807

#SPJ4

Write the equation for the circle graphed below. Center = (-5, -5) Radius= 4

Answers

Answer:

(x + 5)^2 + (y + 5)^2 = 16.

Step-by-step explanation:

(x - a)^2 + (y - b)^2 = r^2    where (a, b) is the centre and r =- the radius.

Here (a, b) = (-5, -5) and r = 4, so:

(x - (-5))^2 + (y - (-5))^2 = 4^2

(x + 5)^2 + (y + 5)^2 = 16

What is the value of 200 + 3 (8 3/4) + 63.25

Answers

Answer:

289.5

Step-by-step explanation:

200+26.25+63.25

289.5

The following graph shows a proportional relationship.
What is the constant of proportionality between

yy and

xx in the graph?

Answers

The constant of proportionality between y and x in the graph is 3

What is the constant of proportionality between y and x in the graph?

From the question, we have the following parameters that can be used in our computation:

The graph

On the graph, we have the following readings

(x, y) = (1, 3)

Using the above as a guide, we have the following:

The constant of proportionality between y and x in the graph is

k = y/x

substitute the known values in the above equation, so, we have the following representation

k = 3/1

Evaluate

k = 3

Hence, the constant of proportionality between y and x in the graph is 3

Read more about proportional relationship at

https://brainly.com/question/28651666

#SPJ1

A golfer at G wishes to hit a shot between two trees P and Q, as shown in the
diagram to the right. The trees are 31 metres apart, and the golfer is 74 metres
from P and 88 metres from P. Find the angle within which the golfer must play
the shot, correct to the nearest degree.

Answers

Answer:

  20°

Step-by-step explanation:

You want the measure of angle G in triangle GPQ with side lengths GP=74, PQ=31, QG=88 meters.

Law of cosines

The law of cosines tells you the relevant relationship is ...

  PQ² = GP² +GQ² -2·GP·GQ·cos(G)

Solving for angle G gives ...

  G = arccos((GP² +GQ² -PQ²)/(2·GP·GQ))

  G = arccos((74² +88² -31²)/(2·74·88)) = arccos(12259/13024)

  G ≈ 19.735° ≈ 20°

The golfer must play the shot within an angle of about 20°.

Other Questions
What is the probability of randomly selecting a quarter from a bag that has 5 dimes, 6 quarters, 2 nickels, and 3 pennies? 1/8 3/16 3/8 5/16 Havermill Co. Establishes a $360 petty cash fund on September 1. On September 30, the fund is replenished. The accumulated receipts on that date represent $84 for Office Supplies, $159 for merchandise inventory, and $33 for miscellaneous expenses. The fund has a balance of $84. On October 1, the accountant determines that the fund should be increased by $72. The journal entry to record the establishment of the fund on September 1 is: Multiple Choice Debit Cash $360; credit Petty Cash $360. Debit Petty Cash $360; credit Accounts Payable $360. Debit Miscellaneous Expense $360; credit Cash $360. Debit Petty Cash $360; credit Cash $360. Debit Cash $360; credit Accounts Payable $360 Look at the map and choose the correct option with the country indicated on the map.Map of Central and South America. The country south to Brazil and with the Atlantic Ocean to its east is highlighted. El Salvador Uruguay Costa Rica Venezuela The maximum allowable resistance for an underwater cable is one hundredth of an ohm permeter and the resistivity of copper is 1. 54 x 10-80m. a) Calculate the smallest cross sectional area of copper cable that could be used. Write a essay explaining Do you think it was a wise political move for President Nixon to visit Communist China and the Soviet Union? Write a letter to the editor of a national newspaper complaining about the bad nature of road in your community,and giving at least 3 reasons why something should be done urgently An artist is sculpting a spherical statue that has a diameter of 10 inches. if the clay to sculpt the statue weighs approximately 1.1 oz/in3 what is the weight of the statue to the nearest ounce? Fully simplify 3(w+11)/6w As a reward for Musa's diligence and agreement, his father decided to distribute a sum of money amounting to 5,800 dinars to him and his brothers, the one with the highest average taking the largest amount, while that the one with the third rank gets an amount that is half of what the one with the first rank takes. Translate this situation as an equation with an unknown X, where X is the amount that the first rank takes. Solve the resulting equation , Solve an exact value . Gives exclusively between two consecutive natural numbers Each of the three sums Toothpicks are used to make a grid that is60toothpicks long and32toothpicks wide. How many toothpicks are used altogether? There are 160 customers at Harris Teeter. 48 of them are children.What percent of the customers at Harris Teeter are adults?PLEASE I NEED EXPLANATION What is the authors purpose for a paragraph that begins with these statements if your car is overheating, turn off the heater immediately Question 13 of 15Why did Confucius develop and promote his teachings in China?OA. He thought that citizens should have the right to pick their ownleaders.B. He believed that people could be saved only if they prayed to theone true god.C. He hoped to bring stability to a country experiencing war andchaos.D. He wanted to teach children to question their parents andteachers.HELP ME ASAP DUE TONIGHT!!! How does the structure of the human digestive system support its function?Answer options with 4 optionsA. The thin walls of the stomach and intestine allow water to enter easily. B. The muscular walls of the system push food and waste through the body. C. The system contains blood vessels to add oxygen to the blood during digestion. D. The cells of the esophagus have rigid membranes to force food into the stomach kim volunteers to work on saturday night after the manager states thebusiness is short staffed and may not meet its monthly production goal.kim is demonstrating: Ortion ofa student is randomly chosen from the group.what is the probability that the student likes cola b and does not like cola a?o 0.10.20.3o 0.4 3. Take f(x, y) = Y. Show that this function is differentiable at (0, 0) (you can only use the definition of differentiability). Is this function differentiableat all points in R^2? I need help on this assignment How does each level of party committees help elect candidates to the office? Borrar la seleccinPregunta 2: En una restaurante para 94 personas hay 19 mesas en las se puedensentar 4,5 o 6 personas. Si sabemos que en el total de mesas con 4 5 sillas sepueden acomodar 64 personas, Cuntas mesas tienen 4 sillas?