The College Board originally scaled SAT scores so that the scores for each section were approximately normally distributed with a mean of 500 and a standard deviation of 100. Assuming scores follow a bell-shaped distribution, use the empirical rule to find the percentage of students who scored less than 400. a. 84% b. 16%

Answer:

[tex]x=15\sqrt{5}[/tex]

Step-by-step explanation:

[tex]15 \times \sqrt{5} = x[/tex]

[tex]33.54102 \approx x[/tex]

Answer:

3889

Step-by-step explanation:

you add all the numbers to get the answer

Answer:3889

Step-by-step explanation:So what u want to do is add them

1034

1289

1566

3889

4 and 5!

4 squared is 16, which is less than 24, and 5 squared is 25, which is more than 24!

[tex]\sqrt{24}[/tex] lies between two consecutive numbers  4  and 5

Given :

Given square root of 24

Lets write all the perfect square numbers

[tex]\sqrt{4}=2\\\sqrt{9}=3\\\sqrt{16} =4\\\sqrt{25} =5\\\sqrt{36} =6\\\sqrt{49}=7[/tex]

From the above perfect square root numbers, we can see that square root (24) lies between [tex]\sqrt{16} \; and\; \sqrt{25}[/tex]

So we can say that [tex]\sqrt{24}[/tex] lies between 4  and 5

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Add the rooms together to find total square yards:

104.8 + 17.4 + 165.8 = 288 square yards

Add the costs together: 13.95 + 2.75 + 5.75 = $22.45 per square yard

For total cost, multiply total square yards by total cost per square yard

288 x 22.45 = 6,465.60

Total cost: $6,465.60

The total job cost Gracie is $6,465.60.

Step 1:

Add the rooms together to find total square yards

=104.8 + 17.4 + 165.8

= 288 square yards

Step 2:

Add the costs together

= 13.95 + 2.75 + 5.75

= $22.45 per square yard

Step 3:

For total cost, multiply total square yards by total cost per square yard

=288 x 22.45

= 6,465.60

Therefore, the total cost: $6,465.60

To calculate the total cost of work done, refer,

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Answer:

obtuse

isosceles

Step-by-step explanation:

It has one angle bigger than 90 so it is obtuse

It has two angles that measure the same so it has two sides that measure the same so it is isosceles

The given triangle is an Obtuse triangle.

A triangle is a three sided polygon, which has three vertices and three angles which has the sum 180 degrees.

We have to given that;

All the angles are,

100°

40°

40°

Here, It has one angle bigger than 90 so it is obtuse.

And, It has two angles that measure the same so it has two sides that measure the same so it is isosceles.

Thus, The given triangle is an Obtuse triangle.

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Answer:

Persia should measure the length of each flower that she used in creating this flower arrangement and add up all the values to get the total height (i.e., the combined height) of the eight flowers used. Make sure to keep the units consistent all throughout the calculation to avoid any errors. For example, if centimetres are used to measure height of one flower, use centimetres all throughout and not switch to using inches at any point.

Hope that answers the question, have a great day!

Answer:

61 1/2

Step-by-step explanation:

math is ez

Answer:

a)

[tex]P(X = 0) = h(0,100,15,5) = \frac{C_{5,0}*C_{95,15}}{C_{100,15}} = 0.4357[/tex]

[tex]P(X = 1) = h(1,100,15,5) = \frac{C_{5,1}*C_{95,14}}{C_{100,15}} = 0.4034[/tex]

[tex]P(X = 2) = h(2,100,15,5) = \frac{C_{5,2}*C_{95,13}}{C_{100,15}} = 0.1377[/tex]

[tex]P(X = 3) = h(3,100,15,5) = \frac{C_{5,3}*C_{95,12}}{C_{100,15}} = 0.0216[/tex]

[tex]P(X = 4) = h(4,100,15,5) = \frac{C_{5,4}*C_{95,11}}{C_{100,15}} = 0.0015[/tex]

[tex]P(X = 5) = h(5,100,15,5) = \frac{C_{5,5}*C_{95,10}}{C_{100,15}} = 0.00004[/tex]

b) 0.154% probability that there are at least 4 defective welders in the sample

Step-by-step explanation:

The welders are chosen without replacement, so the hypergeometric distribution is used.

The probability of x sucesses is given by the following formula:

[tex]P(X = x) = h(x,N,n,k) = \frac{C_{k,x}*C_{N-k,n-x}}{C_{N,n}}[/tex]

In which

x is the number of sucesses.

N is the size of the population.

n is the size of the sample.

k is the total number of desired outcomes.

Combinations formula:

[tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

In this question:

100 welders, so [tex]N = 100[/tex]

Sample of 15, so [tex]n = 15[/tex]

In total, 5 defective, so [tex]k = 5[/tex]

(a) Determine the PMF of the number of defective welders in your sample?

There are 5 defective, so this is P(X = 0) to P(X = 5). Then

[tex]P(X = x) = h(x,N,n,k) = \frac{C_{k,x}*C_{N-k,n-x}}{C_{N,n}}[/tex]

[tex]P(X = 0) = h(0,100,15,5) = \frac{C_{5,0}*C_{95,15}}{C_{100,15}} = 0.4357[/tex]

[tex]P(X = 1) = h(1,100,15,5) = \frac{C_{5,1}*C_{95,14}}{C_{100,15}} = 0.4034[/tex]

[tex]P(X = 2) = h(2,100,15,5) = \frac{C_{5,2}*C_{95,13}}{C_{100,15}} = 0.1377[/tex]

[tex]P(X = 3) = h(3,100,15,5) = \frac{C_{5,3}*C_{95,12}}{C_{100,15}} = 0.0216[/tex]

[tex]P(X = 4) = h(4,100,15,5) = \frac{C_{5,4}*C_{95,11}}{C_{100,15}} = 0.0015[/tex]

[tex]P(X = 5) = h(5,100,15,5) = \frac{C_{5,5}*C_{95,10}}{C_{100,15}} = 0.00004[/tex]

(b) Determine the probability that there are at least 4 defective welders in the sample?

[tex]P(X \geq 4) = P(X = 4) + P(X = 5) = 0.0015 + 0.00004 = 0.00154[/tex]

0.154% probability that there are at least 4 defective welders in the sample

Answer:

Step-by-step explanation:

r(t) = (7 cost + 7t sin t)i + (7 sin t - 7t cos t)j

[tex]\frac{d \bar r t}{dt} =(7\frac{d}{dt}\cos t + 7\frac{d}{dt} (t \sin t)i+(7\frac{d}{dt} \sin t-7\frac{d}{dt} t \cos t)j[/tex]

[tex]=(7(-\sin t)+7(1* \sin t+t \cos t))i+(7 \cost -7(1*\cos t - t \sin t))j\\\\=7((-\sin t+\sin t+t \cos t)i+(\cos t-\cos t+t \sin t)j)\\\\=7((t\cos t)i+(t\sin t)j)[/tex]

[tex]\bar r'(t)=\frac{d \bar r t}{dt} =(7t\cos t)i+(7t\sin t)j---(1)\\\\11\bar r(t)=\sqrt{(7t\cos t)^2+(7t\sin t)^2}\\\\=\sqrt{49t^2(\cos^2t+\sin^2 t)} \\\\=7t[/tex]

[tex]\bar T (t)=\frac{\bar r'(t)}{11\bar r(t)11} =\frac{(7t\cos t)i+(7t\sin t)j}{7t} \\\\\barT(t)=(\cos t)i+(\sin t)j[/tex]

[tex]\bar T'(t)=\frac{d}{dt} (\cos t)i+\frac{d}{dt} (\sin t) j\\\\\bar T'(t)=(-\sin t)i+(\cos t)j---(2)\\\\11\bar T'(t)=\sqrt{(-\sin t)^2+(\cos t)^2} \\\\=\sqrt{\sin^2t+\cos^2t} \\\\=1[/tex]

[tex]\bar N(t)=\bar T'(t)=\frac{(-\sin t)i+(\cos t)j}{(1)} \\\\ \large \boxed {\bar N(t)=(-\sin t)i+(\cos t)j}[/tex]

[tex]K(t)=\frac{|\b\r T'(t)|}{\bar r (t)|} \\\\=\frac{|-\sin t i+\cos t j|}{|7t\cos t +7t \sin t j|}[/tex]

Using eq (1) and (2)

[tex]K(t)=\frac{\sqrt{(-\sin t)^2+(\cos t)^2} }{\sqrt{(7t\cos t)^2+(7t\sin t)^2} }\\\\=\frac{\sqrt{\sin^2 t+\cos^2t} }{\sqrt{49t^2(\cos^2 t+\sin^2t)} }\\\\=\frac{\sqrt{1} }{\sqrt{49t^2\times 1} } \\\\ \large \boxed {K(t)=\frac{1}{7t} }[/tex]

2. The integration region,

[tex]\left\{(r,\theta)\mid\dfrac\pi6\le\theta\le\dfrac\pi2\land2\le r\le3\right\}[/tex]

corresponds to what you might call an "annular sector" (i.e. the analog of circular sector for the annulus or ring). In other words, it's the region between the two circles of radii [tex]r=2[/tex] and [tex]r=3[/tex], taken between the rays [tex]\theta=\frac\pi6[/tex] and [tex]\theta=\frac\pi2[/tex]. (The previous question of yours that I just posted an answer to has a similar region with slightly different parameters.)

You can separate the variables to compute the integral:

[tex]\displaystyle\int_{\pi/6}^{\pi/2}\int_2^3r^2\sin^2\theta\,\mathrm dr\,\mathrm d\theta=\left(\int_{\pi/6}^{\pi/2}\sin^2\theta\,\mathrm d\theta\right)\left(\int_2^3r^2\,\mathrm dr\right)[/tex]

which should be doable for you. You would find it has a value of 19/72*(3√3 + 4π).

3. Without knowing the definition of the region D, the best we can do is convert what we can to polar coordinates. Namely,

[tex]r^2=x^2+y^2[/tex]

so that

[tex]\displaystyle\iint_De^{x^2+y^2}\,\mathrm dA=\iint_Dre^{r^2}\,\mathrm dr\,\mathrm d\theta[/tex]

Answer:

first answer is x= -5 second answer is y=7.

Step-by-step explanation:

7-5=2. 2+3=5.

7-1=6.

Answer: A = (7ft + x)*(6ft + x)

Step-by-step explanation:

The area of a rectangle is equal to A = L*W

where W is width and L is lenght.

Here we have that the width is 6 feet + x feet and the lenght is 7 feet + x feet

(because we also are counting the area of the sidewalk)

Then the total area is:

A = (7ft + x)*(6ft + x)

The value of X is 3.25

Look at the attached picture

Hope it will help you

Good luck on your assignment

Answer:

a) [tex]r(t)=5t[/tex]

b) [tex]A=\pi\cdot r^2[/tex]

c) [tex]A=\pi\cdot (5t)^2[/tex]

d) [tex]A=25\pi t^2[/tex]

Step-by-step explanation:

We know that the circle is increasing its radio from an initial state of r=0 cm, at a rate of 5 cm/s.

This can be expressed as:

[tex]r(0)=0\\\\dr/dt=5\\\\r(t)=r(0)+dr/dt\cdot t=0+5t\\\\r(t)=5t[/tex]

a) Radius of the circle, r (in cm), in terms of the number of seconds, t since the circle started growing:

[tex]r(t)=5t[/tex]

b) Area of the circle, A (in square cm), in terms of the circle's radius, r (in cm):

[tex]A=\pi\cdot r^2[/tex]

c) Circle's area, A (in square cm), in terms of the number of seconds, t, since the circle started growing:

[tex]A=\pi\cdot r^2\\\\A=\pi\cdot (5t)^2[/tex]

d) Expanded form for the area A:

[tex]A=\pi\cdot (5t)^2=25\pi\cdot t^2[/tex]

The function whose graph is given is y = sin (x - 2).

Option B is the correct answer.

A function has an input and an output.

A function can be one-to-one or onto one.

It simply indicated the relationships between the input and the output.

Example:

f(x) = 2x + 1

f(1) = 2 + 1 = 3

f(2) = 2 x 2 + 1 = 4 + 1 = 5

The outputs of the functions are 3 and 5

The inputs of the function are 1 and 2.

We have,

The graph of y = sin(x - 2) is a sinusoidal function that is shifted 2 units to the right from the standard sine function y = sin(x).

The sine function oscillates between -1 and 1 as x increases, and the value of x at which the function reaches its minimum or maximum value is a multiple of π.

When we subtract 2 from x in the equation y = sin(x - 2), the entire graph is shifted to the right by 2 units, which means that the minimum and maximum points occur at x-values that are 2 units greater than they would be for the standard sine function.

The graph of y = sin(x - a) is a sinusoidal function that is shifted a units to the right from the standard sine function.

So, in this case, the graph of y = sin(x-2) looks like the standard sine function shifted 2 units to the right.

The amplitude and period of the function remain the same as the standard sine function, but the phase shift changes.

Thus,

The function whose graph is given is y = sin (x - 2).

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Answer:

a-3b+4

Step-by-step explanation:

1/2 (2a−6b+8) =

=1/2*2a-1/2*6b+1/2*8

=a-3b+4

Answer:

a - 3b + 4

Explanation:

According to the instructions, we must apply the distributive property to create an equivalent expression.

* reminder

distributive property formula: a (b + c) = ab + ac

Let's start by applying the distributive property to the expression.

[tex]\displaystyle\frac{1}{2} (2a - 6b + 8)\\\\\displaystyle\frac{1}{2} (2a) + \displaystyle\frac{1}{2} (-6b) + \displaystyle\frac{1}{2} (8)[/tex]

Simplify by multiplying.

[tex]\displaystyle\frac{1}{2}(2a)+\displaystyle\frac{1}{2}(-6b)+\displaystyle\frac{1}{2}(8)\\\\a+\displaystyle\frac{1}{2}(-6b)+\displaystyle\frac{1}{2}(8)\\\\a-3b+\displaystyle\frac{1}{2}(8)\\\\a-3b + 4[/tex]

Therefore, an equivalent expression to the given expression is a - 3b + 4.

Answer:

36,000

Step-by-step explanation:

So all we have to do is divide 360 by 0.01. that equals 36,000

Answer:

The inequality representing the time taken by the entire cycle is:

[tex]4x+y\leq 3[/tex]

Step-by-step explanation:

The time taken to complete one cycle of a manufacturing machine is no longer than 3 minutes.  

It is provided that the manufacturing machine has two processes.

One of them is repeated 4 times and the second only once.

Assume that the variable x represents the time taken to complete the first process once.

Then the  time taken to complete the first process 4 times would be, 4x.

Also assume that the variable y represents the time taken to complete the second process.

Then the inequality representing the time taken by the entire cycle is:

[tex]4x+y\leq 3[/tex]

Consider the graph below representing the above equation.

Answer: D

Step-by-step explanation:

Answer:123456

Step-by-step explanation:

Answer:

Step-by-step explanation:

you just do, everyone in here needs help so i dont think theres people in here just messing arround, you can trust.

Answer:

because we are amazing as always.

Step-by-step explanation:

Please dont do this or i will report u.

bye

Answer:

2700000

Step-by-step explanation:

Because it is not at 750000 it gets rounded down

Answer:

Each mixture has the same amount of salt for every 1 cup of water.

Step-by-step explanation:

It is provided that:

The ratio of the number of teaspoons of salt to the number of cups of water is 1 : 3 in Nia's solution.

On dividing the amount of salt and the amount of water by 3, the ratio will be the same.

[tex]\text{Salt}: 1\div3=\frac{1}{3}\\\\\text{Water}:3\div3=1\\[/tex]

Thus 1 : 3 is equivalent to the ratio [tex]\frac{1}{3}:1[/tex], which means that Nia's solution has [tex]\frac{1}{3}[/tex]teaspoon of salt for every cup of water.

The ratio of the number of teaspoons of salt to the number of cups of water is [tex]\frac{1}{2}:1\frac{1}{2}[/tex] in Trey’s solution.

On dividing the amount of salt and the amount of water by [tex]1\frac{1}{2}[/tex], the ratio will be the same.

[tex]\text{salt}:\frac{1}{2}\div 1\frac{1}{2}=\frac{1}{3}\\\\\text{Water}:1\frac{1}{2}\div1\frac{1}{2}=1[/tex]

So Trey’s ratio is also equal to the ratio [tex]\frac{1}{3}:1[/tex].

Since each mixture has the same amount of salt for every 1 cup of water, they are equally salty and taste the same.

Answer:

99.36% probability that the sample proportion will differ from the population proportion by less than 6%

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal probability distribution

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

For a sample proportion p in a sample of size n, we have that the sampling distribution of the sample proportions has [tex]\mu = p, s = \sqrt{\frac{p(1-p)}{n}}[/tex].

In this question:

[tex]n = 306, p = 0.18, \mu = 0.18, s = \sqrt{\frac{0.18*0.82}{306}} = 0.0220[/tex].

What is the probability that the sample proportion will differ from the population proportion by less than 6%

This is the pvalue of Z when X = 0.18 + 0.06 = 0.24 subtracted by the pvalue of Z when X = 0.18 - 0.06 = 0.12. So

X = 0.24

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{0.24 - 0.18}{0.022}[/tex]

[tex]Z = 2.73[/tex]

[tex]Z = 2.73[/tex] has a pvalue of 0.9968

X = 0.12

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{0.12 - 0.18}{0.022}[/tex]

[tex]Z = -2.73[/tex]

[tex]Z = -2.73[/tex] has a pvalue of 0.0032

0.9968 - 0.0032 = 0.9936

99.36% probability that the sample proportion will differ from the population proportion by less than 6%

Step-by-step explanation:

federal= $4180

(9500*0.11*4)

private=$2660

(9500*0.07*4)

I don't see a square root sign anywhere, so I'll assume the integral is

[tex]\displaystyle\int\sqrt{13+12x-x^2}\,\mathrm dx[/tex]

First complete the square:

[tex]13+12x-x^2=49-(6-x)^2=7^2-(6-x)^2[/tex]

Now in the integral, substitute

[tex]6-x=7\sin t\implies\mathrm dx=-7\cos t\,\mathrm dt[/tex]

so that

[tex]t=\sin^{-1}\left(\dfrac{6-x}7\right)[/tex]

Under this change of variables, we have

[tex]7^2-(6-x)^2=7^2-7^2\sin^2t=7^2(1-\sin^2t)=7^2\cos^2t[/tex]

so that

[tex]\displaystyle\int\sqrt{13+12x-x^2}\,\mathrm dx=-7\int\sqrt{7^2\cos^2t}\,\cos t\,\mathrm dt=-49\int|\cos t|\cos t\,\mathrm dt[/tex]

Under the right conditions, namely that cos(t) > 0, we can further reduce the integrand to

[tex]|\cos t|\cos t=\cos^2t=\dfrac{1+\cos(2t)}2[/tex]

[tex]\displaystyle-49\int|\cos t|\cos t\,\mathrm dt=-\frac{49}2\int(1+\cos(2t))\,\mathrm dt=-\frac{49}2\left(t+\frac12\sin(2t)\right)+C[/tex]

Expand the sine term as

[tex]\dfrac12\sin(2t)}=\sin t\cos t[/tex]

Then

[tex]t=\sin^{-1}\left(\dfrac{6-x}7\right)\implies \sin t=\dfrac{6-x}7[/tex]

[tex]t=\sin^{-1}\left(\dfrac{6-x}7\right)\implies \cos t=\sqrt{7^2-(6-x)^2}=\sqrt{13+12x-x^2}[/tex]

So the integral is

[tex]\displaystyle-\frac{49}2\left(\sin^{-1}\left(\dfrac{6-x}7\right)+\dfrac{6-x}7\sqrt{13+12x-x^2}\right)+C[/tex]

Answer:

Before A. 32.7247330577, A. 27.8204757722, B. 32.7247330577, C. 15.4868329805, and D. 32.7247330577

Step-by-step explanation:

Used a calculator. Not that Hard.

The solution to the given function is determined as 13.

The solution of the function is calculated as follows;

[tex]\sqrt{x - 4} \ +\ 5 = 2[/tex]

collect similar terms together

 [tex]\sqrt{x - 4} \ = 2-5\\\\\sqrt{x - 4} \ = -3[/tex]

square both sides of the equation

[tex](\sqrt{x - 4} )^2 = (-3)^2\\\\x - 4 = 9\\\\x = 9 + 4\\\\x = 13[/tex]

Thus, the solution to the given function is determined as 13.

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Answer:

No solution

Step-by-step explanation:

Edge.