Question

For the data set 7, 5, 10, 11, 12, the mean, x, is 9. What is the standard
deviation?

Answer 1

Standard Deviation is s = 2.9

Explanation:

Count =
`N` = 5

Mean =
`x^-` = 9

Variance =
`s^2` = 8.5

SD Formula =
`s = \sqrt (1)/(N - 1) (x_(i) - x^-)^2`

Variance Formula
`s^2 = ((x_(i) - x^-)^2)/(N- 1)`

Step 1: Calculate the variance

`= ((7-9)^2 + (5-9)^2 + (10-9)^2 + (11-9)^2 + (12 -9)^2 )/(5-1)`

`=(34)/(4) = 8.5`

Step 2: Apply square root/SD formula

`=√(8.5) = 2.9`