Question

1. A sample of 200 students rated their level of admiration for Shakira on a scale of 1 to 7. The mean rating was 5.06, and the standard deviation was 1.50. (For the sake of the exercise, treat the sample as the entire population.)

A. Use the data to demonstrate that the standard deviation of the z distribution is always 1.

2. Credit card companies will often call cardholders if the pattern of use indicates that the card might have been stolen. Let's say that you charge an average of $280 a month on your card, with a standard deviation of $75. The credit card company will call you anytime your purchases for the month exceed the 98th percentile. What is the dollar amount beyond which you'll get a call from your credit card company?

Answer 1