1. Suppose you are testing the following hypothesis:

Ho: = 120

Ha: 120

A random sample of size is 12 is taken from the target population.

Here is this sample.

108.98 127.46 111.56

152.22 107.26 75.71

111.45 93.32 128.58

110.59 91.97 135.11

The = 0.05.

Should the Ho be rejected?

2. Suppose you want to estimate, with 95% confidence, the population mean force required to break the insulator to within +/- 25 pounds.

On the basis of a study conducted the previous year, you believe that the standard deviation is 100 pounds.

Calculate the required sample size.