Question

In the data set below, what is the variance? 9 8 9 5 9 If the answer is a decimal, round it to the nearest tenth. variance (σ2):

Answer 1

2.4

Explanation:

Step 1: Find the mean.

The mean (or average) of the data set is found by adding all the numbers in the data set and subtracting by the number of numbers, as shown below.

`(9+8+9+5+9)/(5)=(40)/(5)=8`

Step 2: Find the standard deviation.

Find the standard deviation by subtracting the mean from each of the numbers in the data set and squaring the result:

`(9-8)^(2)+(8-8)^(2)+(9-8)^(2)+(5-8)^(2)+(9-8)^(2)`

`1+0+1+9+1 = 12`

Step 3: Find the variance.

Divide the standard deviaton by the number of numbers to get the variance.

Variance =
`(12)/(5)` OR 2.4

Hope this helps!

Answer 2

2.4

Explanation:

We would first calculate the mean, because we would need it to calculate our varance.

Mean= sum of the number of given data set/ total number

Mean = (9 +8 +9 +5 +9 )/5

= 40/5= 8

variance (σ2):= [(9-8)^2 + (8-8)^2 + (9-8)^2 +(5-8)^2 +(9-8)^2]/5

=( 1+ 0 + 1 +9 +1)/5

= 12/5

variance (σ2)= 12/5

=2.4