Question

The following data points are last week's revenues (in thousands of dollars) for the

5 Herman's Hoagies locations.

5,6,5,10,9
Find the standard deviation of the data set.
Round answers to nearest hundreth.

Answer 1

2.10

Explanation:

Mean: (5+6+5+10+9)/5

= 7

Sum of squares:

5²+6²+5²+10²+9²

= 267

Variance = 267/5 - 7²

= 4.4

sd = sqrt(4.4)

sd = 2.097617696

Answer 2

3.14 thousand dollars

Explanation:

Standard deviation is the average distance of your data values from the mean (basically, how far off you were from the center). We calculate standard deviation or σ by taking each value, subtracting it from the mean, squaring it, then dividing by the mean.

First, we need to find the mean, which is the sum of all values / number of values.

5 + 6 + 5 + 10 + 9 = 35 / 5 = 7

Take the absolute value of the difference of each value from 7:

5 - 7 = 2

6 - 7 = 1

5 - 7 = 2

10 - 7 = 3

9 - 7 = 2

Square each of these values and add them together:

2^2 + 1^2 + 2^2 + 3^2 + 2^2 = 22

Divide the sum by the mean:

22 / 7 = 3.14

The standard deviation is 3.14 thousand dollars.