Hannah uses a store gift card to pay for 3 pair of pants priced at $27 each. What is the change in the value of the store gift card?

If the gift card is $30 the remaining change is 3 dollars

---- sample standard deviation

---- sample variance

Step-by-step explanation:

Solving (a): The sample variance

First, we calculate the midpoint of each class (this is the average of the limits)

So, we have:

And so on

So, the table becomes:

Calculate the mean

The variance is:

So, we have:

The sample standard deviation is:

Solving (b): The sample variance

In (a), we calculate the sample variance to be: