Chapter Title is Sampling Methods and the Central Limit Theorem:

We have to use the Z (area's under the normal curve) and student's t distribution charts. These are very confusing to read and find the data in the body of the chart.

Question #1 is:

A population of unknown shape has a mean of 75. You select a sample of 40. The standard deviation of the sample is 5. Compute the probability the sample mean is:

a) Less than 74

b) Between 74 and 76

c) Between 76 and 77

d) Greater than 77

Question #2 reads:

According to a study, it takes 330 minutes for taxpayers to prepare a 1040 tax form. An agency selects a random sample of 40 taxpayers and finds a standard deviation of the time to prepare a form 1040 is 80 minutes.

a) What assumptions do you need to make anout the shape of the population?

a) What is the standard error of the mean in this example?

b) What is the likelihood the sample mean is greater than 320 minutes?

c) What is the likelihood the sample mean is between 320 and 350 minutes?

d) What is the likelihood the sample mean is greater than 350 minutes?