MCQS Precalculus
1) A medical clinic in a small city in the state of Washington wants to estimate the mean serum cholesterol level (measured in mg of cholesterol per 100 mL of blood) of teenage males. Based on the following summary data taken from a random sample of 10 teenage males from this community, compute a 90% confidence interval for the mean serum cholesterol level of teenage males in this city. Assume that the sample was taken from a normal distribution. Round your confidence limits to 2 decimal places.
Summary Data: n = 10, , s = 24.920
Choose one answer.
A. (207.15, 240.67)
B. (209.12, 238.01)
C. (210.12, 239.56)
D. (213.34, 242.83)
E. None of the above
2) Questions on a statistics exam are considered good questions provided the questions discriminate between students who have studied for the exam and those who have not studied. Suppose that on a particular statistics exam the students were separated into two groups, the group that studied and the other group that had not studied. Data was collected and a 95% confidence interval for the difference in the proportion of those passing the exam from the group that studied and the proportion of those passing the exam from the group that had not studied. The confidence interval turned out to be . Note that sample 1 is from the group that studied and sample 2 is from the group that did not study. Select the best answer.
Choose one answer.
A. The data fails to show with 95% confidence that these questions discriminated between those who studied and those who did not study.
B. We are 95% confident that those who studied had a higher passing rate than those who did not study.
C. We are 95% confident that those who studied had a lower passing rate than those who did not study.
D. None of the these are correct.
