3. The teachers union is concerned about the amount of time teachers spend each doing schoolwork at home. A simple random sample of 56 teachers had a mean of 8.0 hours per
week working at home after school. Assume that the population standard deviation is 1.5
hours per week.
a) Construct a 95% confidence interval estimate for the mean number of hours per week a
teacher spends working at home.
b) Does the confidence interval support that teachers work at home after school more than 10
hours a week? Why or why not?