how do I find the standard deviation in a given sample?

Question

Hypothetical Miles per Gallon for Large SYV'S

1 5 1

2 5 4

3 5 5

4 5 5

5 5 10

2 column is mpg sample 1 and 3rd column is mpg sample 2

Answer 1

Use a TI-84 type calculator and input the data under STAT, Edit, L1 L2, then go back to STAT CALC 1-Var Stats and it gives you for L2, standard deviation.

For the 2nd column, the standard deviation = 0 because there is no variation.

For the 3rd column, the standard deviation is 2.9 and the average = 5