Example 2

EXAMPLE 2 Calculating the overall sample mean

For the sample GPA data given in Table 1 for Dorms A, B, and C, calculate the overall sample mean, .

Solution

We have dormitories, with sample mean GPAs , , . Also, , and . Thus,

All the sample sizes are equal, so we can also calculate as follows:

NOW YOU CAN DO

Exercises 11–14.