1)
and
. Sam calculates a 90% confidence interval for the population mean, assuming that
. John calculates a 90% confidence interval, assuming that
is unknown. Which of the following is true?
A)Sam’s interval is narrower than John’s.
B)Sam’s interval is wider than John’s.
C)Sam and John calculate the same interval.
D)There is not enough information to tell.
2)A study reports that only 12% of people stick to their New Year’s resolutions. You are considering whether to sample 100 people or 200 people to verify the results of the study. With which sample size are you more likely to find a sample proportion that is close to the population proportion?
A)100
B)200
C)It doesn’t matter because a large sampling error is still possible with a large sample size.
D)It doesn’t matter because the probability of finding some range of sample means does not depend on sample size.
