1.) If we didn't know the proportion of students that expect to drop the class, and we wanted to estimate a 90% CI with a margin of error of 2%. Then the sample size needed would be?

options:

49

2401

3383

1692

2.) Suppose that we also have reason to believe (from previous studies) that the population standard deviation of credit card debts for this group is $100. What is the sample size needed to reduce the Margin of Error to $10 for a 99% confidence interval?

options:

664

20

385

26

3.) The weights lost by a random sample of 17people have a mean of 9.4 pounds and a standard deviation of 3.1 pounds. Assume that the weights lost have a normal distribution. Calculate a 80% confidence interval for the true average weight lost.

If for the above problem the mean and standard deviation stay the same and the alpha level increased, which of the following would change?

options: (more than one can be correct)

Point Estimate

Standard Error

Margin of Error

Critical Value