#### Consider the drying time data for Exercise 1.1 on page 13. Compute the sample variance and sample standard deviation.

## Solution:

We know, based on our answer in Exercise 1.1, that the sample mean is .

To compute for the sample variance, we shall use the formula

The formula states that we need to get the sum of , so we can use a table to solve for every sample.

The table above shows thatÂ

Therefore, the variance is

The standard deviation is just the square root of the variance. That is