Answer: σ² = 2.90
Step-by-step explanation: For a frequency table, population variance is calculated by:
[tex]\sigma^{2}=\frac{\Sigma f(x-\mu)^{2}}{\Sigma f}[/tex]
where
f is frequency
μ is expected value or mean of the distribution
In this case, mean of the distribution for a grouped frequency table is calculated by:
[tex]\mu=\Sigma x.f(x)[/tex]
where
x is (as the data is grouped) the mid value of the response time
So, the table is
x | f
6.45 | 18
7.45 | 21
8.45 | 34
9.45 | 46
10.45 | 46
11.45 | 25
12.45 | 21
And mean will be:
[tex]\mu=6.45(18)+7.45(21)+8.45(34)+9.45(46)+10.45(46)+11.45(25)+12.45(21)[/tex]
μ = 9.5874
To calculate the variance, the formula above is transformed into
[tex]\sigma^{2}=\frac{\Sigma f.x^{2}-\frac{(\Sigma f.x)^{2}}{\Sigma f} }{\Sigma f}[/tex]
So, to facilitate the calculations, divide each term in a table:
f | x | f.x | f.x²
18 | 6.45 | 116.1 | 748.845
21 | 7.45 | 156.45 | 1165.5525
34 | 8.45 | 287.3 | 2427.685
46 | 9.45 | 434.7 | 4107.915
46 | 10.45 | 480.7 | 5023.315
25 | 11.45 | 286.25 | 3277.5625
21 | 12.45 | 261.45 | 3255.0525
∑ 211 | | 2022.95 | 20005.9275
Population variance will be:
[tex]\frac{(\Sigma f.x)^{2}}{\Sigma f} =[/tex] [tex]\frac{(2022.95)^{2}}{211}[/tex] = 19394.9133
[tex]\sigma^{2}=\frac{\Sigma f.x^{2}-\frac{(\Sigma f.x)^{2}}{\Sigma f} }{\Sigma f}[/tex]
[tex]\sigma^{2}=\frac{20005.9275-19394.9133}{211}[/tex]
σ² = 2.90
The population variance for the response time for EMTs is 2.90.
pplease help me!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Answer:
1/125
Step-by-step explanation:
Negative exponents don't make the number negative, it means that you divide the number by itself. So 1/(5×5×5) which is 1/125.
Answer:
the last one - 1/125
Step-by-step explanation:
325 x 454 ≈ __________ x __________ = 150,000
can somone help me with this one
Answer: 300 x 500=150,000
Step-by-step explanation: Here, they're asking you to create a ballpark estimate by rounding. Since most people can't multiply 325 by 454 in their heads, it's more ideal to simply round to get an estimate first. Here, the numbers are rounded to the nearest hundred for a more friendly equation. The ≈ sign means approximately equals, or about, which indicates that your answer is close but not exact.
Hope this helps,
Lacia :)
hi please help quick
1 7/12 + 4 1/3
A. 5 8/15
B. 5 11/12
C. 3 3/12
D. 3 6/9
Answer: B
Step-by-step explanation:
Answer:
B. 5 11/12
Step-by-step explanation:
Simplify the following:
1 + 7/12 + 4 + 1/3
Put 1 + 7/12 + 4 + 1/3 over the common denominator 12. 1 + 7/12 + 4 + 1/3 = 12/12 + 7/12 + (12×4)/12 + 4/12:
12/12 + 7/12 + (12×4)/12 + 4/12
12×4 = 48:
12/12 + 7/12 + 48/12 + 4/12
12/12 + 7/12 + 48/12 + 4/12 = (12 + 7 + 48 + 4)/12:
(12 + 7 + 48 + 4)/12
| 2 |
| 4 | 8
| 1 | 2
| | 7
+ | | 4
| 7 | 1:
Answer: 71/12 = Convert to a mixed number:
71/12
Divide 71 by 12:
1 | 2 | 7 | 1
12 goes into 71 at most 5 times:
| | | 5
1 | 2 | 7 | 1
| - | 6 | 0
| | 1 | 1
Read off the results. The quotient is the number at the top and the remainder is the number at the bottom:
| | | 5 | (quotient)
1 | 2 | 7 | 1 |
| - | 6 | 0 |
| | 1 | 1 | (remainder)
The quotient of 71/12 is 5 with remainder 11, so:
Answer: 5 11/12
What is the height of a solid cylinder with a mass of 26.05 g, a diameter of 3.56 cm, and a density of 2.72 g/cm^3?
Answer:
h = 0.962 cm
Step-by-step explanation:
Given that,
Mass of a solid cylinder, m = 26.05 g
The diameter of a cylinder, D = 3.56 cm
Radius, r = 1.78 cm
The density of a cylinder is 2.72 g/cm³
We need to find the height of the cylinder. Let it is h. We know that mass per unit volume is equal to density of an object. It can be given by :
[tex]d=\dfrac{m}{V}\\\\d=\dfrac{m}{\pi r^2 h}\\\\h=\dfrac{26.05}{\pi \times (1.78)^2\times 2.72}\\\\h=0.962\ cm[/tex]
So, the height of the cylinder is 0.962 cm.
which one is right?
l/w or w/l
the w is width and the l is length
10 1/9+5 14/15
what is the sum ?
Please help
Answer:
16 2/45
Step-by-step explanation:
10 + 5= 15
1/9 + 14/15= 47/45
47/45= 1 2/45
1 2/45 + 15= 16 2/45
18) Solve each equation for the given variable.
C = 21 r Solve for r
Answer:
r=c/21
Step-by-step explanation:
The radius of a right circular cone is increasing at a rate of 5 inches per second and its height is decreasing at a rate of 3 inches per second. At what rate is the volume of the cone changing when the radius is 50 inches and the height is 20 inches
Answer:
1700π in³/s
Step-by-step explanation:
Volume of a cone is expressed as
V = 1/3πr²h
Given
dr/dt = 5in/s
dh/dt = 3in/s
radius r = 50in
h = 20in
Required
dV/dt = ?
dV/dt = dV/dr * dr/dt + dV/dh*dh/dt
dV/dr = 1/3πh (5) + 1/3πr²(2)
dV/dt = 1/3π(20)(5)+1/3 π(50)²(2)
dV/dt = 100π/3 + 5000π/3
dV/dt = 5100π/3
dV/dt = 1700π in³/s
I need help pls.....
Answer:
Can you take a clear pic pls
Step-by-step explanation:
Three pounds of bananas cost $7. How many pounds of bananas per dollar is that?
Round your answer to the nearest hundredths place.
Answer:
0...
Step-by-step explanation:
Can someone please explain this to me ?
Answer:
Not sure how to explain but your answer is x=11
Step-by-step explanation:
Solve the system by Substitution.
x−y=7
−2x+7y=−19
A. No Solution
B. (6, -1)
C. (7, 6)
D. (6, 5)
Answer:
x=6 y=-1
Step-by-step explanation:
x=7+y
-2(7+y)+7y=-19
x=7+y
-14+5y=-19
x=7+y
5y=-5 ===> y=-1
x=7-1
y=-1
x=6
y=-1
Please help me figure this out
Answer:
Step-by-step explanation:
p-6=-14
p=-8
I NEED THE ANSWER ASAP
tea drinkers in Canada is 4:1. Jack concluded from this that if 400 people
were surveyed, 100 of them would most likely be regular tea drinkers. Is
he correct? Explain.
Answer: He is incorrect.
Step-by-step explanation:
The question says:
"tea drinkers in Canada is 4:1"
We only have that, so i guess that this means:
"The ratio of nonregular tea drinkers to regular tea drinkers in Canada is 4:1"
The ratio 4:1 means that for each 4 non-regular tea drinkers, there is one regular tea drinker.
Now let's multiply both by 100.
For each 400 nonregular tea drinker, there are 100 regular tea drinkers, if we add them we have a total of 500
Then the statement would be if 500 people were surveyed, 100 of the would most likely be regular tea drinkers.
what are the correct factor pairs of 20
Jewelry store buys a gold watch to sell the price of the watch is marked up 45% the store sells the watch for $2610 how much did the jewelry store pay for the watch
Answer:
45 x 2610
100 = 1174.5
Step-by-step explanation:
e collect diswers.
Which statements are true about the function graphed here?
Answer:
Step-by-step explanation:
Just took the test I hope this helps a little
The y-intercept of line is at (0, -6) and the domain is (-∞, ∞). Then the correct options are A and D.
What is the linear system?A linear system is one in which the parameter in the equation has a degree of one. It might have one, two, or even more variables.
The graph of the line is shown below.
The line intersects the y-axis at (0, -6). Then the y-intercept of the line is (0, -6).
The domain of the linear function will be a real number.
And the range of the linear function is also real number.
Then the correct options are A and D.
The graph is given below.
More about the linear system link is given below.
https://brainly.com/question/20379472
#SPJ2
1. In a box full of different fruit 30% of them are apples. If there are 15 apples in
the box, how many total pieces of fruit are in the box?
Your answer
Answer:
50
Step-by-step explanation:
15/x=30/100
30x=1500
x=50
there are 50 apples in the box.
part/whole = percent/100
15/x = 30/100
30x = 1500
x = 50
The distance between the points (2, -4) and (3, 8) is:
Answer:
1,12
Step-by-step explanation:
Find the midpoint of the two points on the circle (-2,1) and (5,-4)
Answer:
1.5,-1.5
Step-by-step explanation:
please pass this on... ( #helpsavelives )
Who ever is reading this:
I love u.
U matter.
The world needs u
hang in there ik it may be bad but u deserve the world <3
ur beautiful no matter ur shape, size, color, gender.. anything
don't give up i need u to live.
i wish i could take everyones problems so yall wouldn't have to have em but i cant so just know ily and if anyone needs to talk u can talk to me
Pls pass this on. Everyone deserves to know this. ♥️♥️
just copy and paste its not hard pls this could save someones life
Answer: (1.5,-1.5)
Step-by-step explanation:
I hope it’s right
What percent of the observations in a distribution lie between the first quartile and the third quartile
Answer:
The value is [tex]k = 50\%[/tex]
Step-by-step explanation:
Generally quartiles divide observation into four parts
The first quartile takes up 25% of the observation
The second quartile takes up 50% of the observation
The third quartile takes up 75% of the observation
The fourth quartile takes up 100% of the observation
Generally the percentage of the observation that lies between the first and the third quartile is mathematically represented as\
[tex]k = 75\% - 25\%[/tex]
=> [tex]k = 50\%[/tex]
Using the concepts of quartiles and percentiles, it is found that 50% of the observations in a distribution lie between the first quartile and the third quartile.
A measure is said to be at the xth percentile of a data-set if it is greater than x% of the observations in the data-set.The first quartile is the 25th percentile, as [tex]\frac{100}{4} = 25[/tex]. The third quartile is the 75th percentile, as [tex]3\frac{100}{4} = 75[/tex].To find the percentage between, we subtract the percentiles, hence:
75 - 25 = 50
50% of the observations in a distribution lie between the first quartile and the third quartile.
A similar problem, which involves percentiles, is given at https://brainly.com/question/24495213
Multiple by 10 and 100
8*10=
Answer:
Step-by-step explanation:
80
If A=(-1, -3) and B=(11,-8), what is the length of AB?
A. 14 units
B. 13 units
C. 12 units
D. 11 units
9514 1404 393
Answer:
B. 13 units
Step-by-step explanation:
The distance formula can be useful.
d = √((x2 -x1)² +(y2 -y1)²)
d = √((11-(-1))² +(-8-(-3))²) = √(12² +(-5)²) = √(144 +25) = √169
d = 13
The length of AB is 13 units.
_____
If you're familiar with a few of the small Pythagorean triples, you would know that for integer coordinates, an integer answer is most likely to be 13. The x- and y-differences in coordinates being 12 and 5 confirm that the (5, 12, 13) triple is being used here.
There are no Pythagorean triples with hypotenuse values of 11, 12, or 14. (3, 4, 5) can be doubled to give (6, 8, 10), but 10 is not a choice.
Select the values that correctly complete the problem.
a = __
b = __
c = __
d = __
e = __
a = ✔ 2
b = ✔ 4
c = ✔ 3
d = ✔ 2
e = ✔ 3
The number of different simple random samples of size 5 that can be selected from a population of size 8 is
Answer:
Number of different simple random samples of size 5 that can be selected from a population of size 8 = 56 ways
Step-by-step explanation:
Step 1: Stating the combination formula
The number of selections of a number n, taking r at a time is given by the formula: [tex]\frac{n!}{(n - r!)r!}[/tex]
From the formula above, n is population size = 8
r is sample size = 5
Step 2: Substituting the values of n and r
Number of possible selections = 8!/(8 -5)*5! = 8!/3! * 5!
Number of possible selections = [tex]\frac{8*7*6*5*4*3*2*1}{3*2*1 * 5*4*3*2*1}[/tex]
Number of possible selections = 56
Therefore, number of different simple random samples of size 5 that can be selected from a population of size 8 = 56 ways
Solve 7 + x - 15 = -2 2/3
Answer: i am 99.9% sure the answer is 16/3 or the other forms of it 5.3 repeating three or mixed number 5 1/3
What is this rate written as a UNIT RATE?
6 miles in 2 hours
Answer:
3 miles in 1 hour
Step-by-step explanation:
6÷2=3 miles
2÷2=1 hour
Which property
If 9x=27, then 27=9x
Answer:
symmetric property
Step-by-step explanation:
x=y then y=x
NASA uses a launch clock to measure time before and after lift-off. It takes 2 hours and 15 minutes of preparations on base, 20 minutes to travel to the launch pad, and 40 minutes of pre-launch checks once in the spacecraft. When should the astronauts begin preparation?
–3 hours 15 minutes, because all the preparation times add to 3 hours and 15 minutes
–3 hours 35 minutes, because all the preparation times add to 3 hours and 35 minutes
–2 hours 35 minutes, because all the preparation times add to 2 hours and 35 minutes
–2 hours 15 minutes, because all the preparation times add to 2 hours and 15 minutes
Answer:
–3 hours 15 minutes, because all the preparation times add to 3 hours and 15 minutes
Step-by-step explanation:
Answer:
a
Step-by-step explanation:
i took the quiz
Could anyone help with “b” on the bottom. I’m not sure what it’s asking. Thank you!!
Answer:
yes
Step-by-step explanation:
the question is asking if the mean helped you find the number that pops up the most, so in this case 3.
by using the mean we will do
0+0+3+3+5+7+2+2+3+3+3+5 divided by 12
giving us a result of 3, in this case YES it does help at better explaining the typical value