P/S Ch. 16/17 Review

Suppose 20% of all incoming freshmen at a large university must take a remedial mathematics course. A random sample of 170 incoming freshmen is selected and the proportion of the sample needing to take a remedial math course (p-hat) is calculated.

What is the standard error for the sampling distribution of p-hat?

• 0.031

• 0.00096

• 5.22

• 0.062

Suppose 20% of all incoming freshmen at a large university must take a remedial mathematics course. A random sample of 170 incoming freshmen is selected and the proportion of the sample needing to take a remedial math course (p-hat) is calculated.

If the size of the sample described was made 4 times larger, what impact would that have on the standard error of the distribution?

• The SE would get 4 times larger

• The SE would get 4 times smaller

• The SE would get 2 times larger

• The SE would get 2 times smaller

Which of the following z* values should be used when constructing a 96% confidence interval?

• 2.05

• 1.96

• 2.33

• 2.58

Which of the following z* values should be used when constructing a 90% confidence interval?

• 1.64

• 1.96

• 1.28

• 2.58

A 95% confidence interval for the true proportion of incoming freshmen to a large university who must complete a remedial mathematics course is constructed: (0.164 , 0.224).

What is the margin of error for the given interval?

• 0.06

• 0.03

• 0.015

• 0.12

A 95% confidence interval for the true proportion of incoming freshmen to a large university who must complete a remedial mathematics course is constructed: (0.164 , 0.224).

How many incoming freshmen were surveyed?

• 668

• 220

• 180

• 557