8. We want to estimate the average amount of time users spend on our website. How many site visits must be randomly selected if we want 99% confidence that the sample mean is within 2 minutes of the population mean? Assume = 10.

Select one:

a.

n= 42

b.

n= 41

c.

n= 25

d.

n= 24

9. To compute a CI for a population, we must establish the values of:

Select one:

a.

A point estimate for p-hat, CL,andn

b.

A point estimate for p, CL,E, andn

c.

A point estimate for p-hat, CL,E, andn

d.

A point estimate for p, CL,andn

10. If you need to estimate the true proportion of some attribute or attitude in a population of interest, you could:

Select one:

a.

Use a point estimate to make an inference about p-hat

b.

Obtain a large, random sample from the population and survey them directly

c.

Use a point estimate to make an inference aboutp

d.

Construct a confidence interval based on x-bar