All categories

3 years ago

Calculate the variance and the standard deviation of the data below 23. 19, 22, 30, 28

Mathematics

1 answer:

Alina [70]3 years ago

7 0

To get the variance, start with finding the mean of your data points:

(23 + 19 + 22 + 30 + 28) / 5 = 24.4

Now take each data point and subtract the mean from it, then square that value:

23 - 24.4 = -1.4 * -1.4 = 1.96

19 - 24.4 = -5.4 * -5.4 = 29.16

22 - 24.4 = -2.4 * -2.4 = 5.76

30 - 24.4 = 5.6 * 5.6 = 31.36

28 - 24.4 = 3.6 * 3.6 = 12.96

Now get the average of those new numbers. That is your variance:

(1.96 + 29.16 + 5.76 + 31.36 + 12.96) / 5 = 16.24

The standard deviation will be the square root of the variance:

√(16.24) = 4.0299 (rounded to 4DP)

You might be interested in

jada has some money she sells 1 balloon for 5cent. Now she has 13cent. How much money did jada have before selling the balloon?

seraphim [82]

Answer:

8 cents

Step-by-step explanation:

To find out how much money Jada had before seling the balloon, we can subtract 5 from 13.

13 - 5 = 8

So, Jada had 8 cents before selling the balloon.

3 0

3 years ago

(−2)(−2)+4 is equal to

abruzzese [7]

Answer:

Step-by-step explanation:

[-2][-2]=-2 x-2=4

4+4=8

8 0

3 years ago

PTC is a substance that has a strong bitter taste for some people and is tasteless for others. The ability to taste PTC is inher

lana66690 [7]

Answer:

a) $n=\frac{0.76(1-0.76)}{(\frac{0.01}{1.64})^2}=4905.83$

And rounded up we have that n=4906

b) For this case since we don't have prior info we need to use as estimatro for the proportion $\hat p =0.5$

$n=\frac{0.5(1-0.5)}{(\frac{0.01}{1.64})^2}=6724$

And rounded up we have that n=6724

Step-by-step explanation:

We need to remember that the confidence interval for the true proportion is given by :

$\hat p \pm z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$

Part a

The estimated proportion for this case is $\hat p =0.76$

Our interval is at 90% of confidence, and the significance level is given by $\alpha=1-0.90=0.1$ and $\alpha/2 =0.05$ . The critical values for this case are:

$z_{\alpha/2}=-1.64, t_{1-\alpha/2}=1.64$

The margin of error for the proportion interval is given by this formula:

$ME=z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$ (a)

The margin of error desired is given $ME =\pm 0.01$ and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=\frac{\hat p (1-\hat p)}{(\frac{ME}{z})^2}$ (b)

Replacing we got:

$n=\frac{0.76(1-0.76)}{(\frac{0.01}{1.64})^2}=4905.83$

And rounded up we have that n=4906

Part b

For this case since we don't have prior info we need to use as estimatro for the proportion $\hat p =0.5$

$n=\frac{0.5(1-0.5)}{(\frac{0.01}{1.64})^2}=6724$

And rounded up we have that n=6724

3 0

3 years ago

What is the value of the expression

Gelneren [198K]

Answer:32

Step-by-step explanation: First you do 4×4×4×

=64 then you divide by 2.. 64÷2=32

8 0

3 years ago

Read 2 more answers

Find The Slope Of The Line

Ulleksa [173]

Answer:

-1/3

Step-by-step explanation:

To find the slope you have to find the rise over run. Start at the first point then go down 3 and over to the right 1. Your slope is -1/3.

4 0

3 years ago

Read 2 more answers