Hump Dayyyyyy

Tonight, please complete the problem on the back of today's notes/example (about credit cards).

• Show the hypotheses, conditions, math and conclusion for a T-Test
• Show the math and interpret a 90% confidence interval (T-interval) for the mean number of credit cards for undergraduates.

Here is the context in case you lost yours...

A credit bureau analysis of undergraduate students’ credit records found that the average number of credit cards in an undergraduate’s wallet was 4.09. (“Undergraduate Students and Credit Cards in 2004,” Nellie Mae, May 2005). It was also reported that in a random sample of 132 undergraduates, the sample mean number of credit cards that the students said they carried was 2.6, with a sample standard deviation of 1.2.

Is there convincing evidence that the mean number of credit cards that undergraduates report carrying is less than the credit bureau’s figure of 4.09?

Tomorrow in class we'll do some AP problems to wrap up chapter 23...then, on Friday, it's on to chapter 24--2 sample t-tests and intervals! Woooo!