More poor sampling designs Repeat the previous exercise for the following scenarios:

a. A principal in a large high school wants to sample student attitudes toward a proposal that seniors must pass a general achievement test to graduate. She lists all of the first-period classes. Then, using a random number table, she chooses a class at random and interviews every student in that class about the proposed test.

b. A new restaurant opened in January. In June, after six months of operation, the owner applied for a loan to improve the building. The loan application asked for the annual gross income of the business. The owner’s record book contains receipts for each day of operation since opening. She decides to calculate the average daily receipt based on a sample of the daily records and multiply that by the number of days of operation in a year. She samples every Friday’s record. The average daily receipt for this sample was then used to estimate the yearly receipts.