3. A reporter for a student newspaper is writing an article on the cost of off-campus housing. A sample was selected of 10 one-bedroom units within a half-mile of campus and the rents paid. The sample mean is $550 and the sample standard deviation is $60.05. Assume this population is normally distributed. What is the 95% confidence interval estimate of the mean rent per month for the population of one- bedroom units within a half-mile of campus? $487.05 to $612.95 $507.05 to $592.95 $477.05 to $622.95 $497.05 to $602.95

A primary measure of dispersion for sample data is the sample standard deviation, s.  Choose the best option to explain what the meaning of the sample standard deviation is, in general.   A. The distance between one observation and the mean. B. The average distance of an observation from the middle of the distribution. C. The average distance between observations in the sample. D. The distance between the third and first quartiles.

4. At private college the achievement test is used for advanced study placement. Counselors selected a random sample of 144 students from the college and scored their tests by hand before sending them in for computer processing. For this sample, the mean was 450 and s = 29. Construct a 98% confidence interval for the mean.

In a survey, 21 people were asked how much they spent on their child's last birthday gift. The results were roughly bell-shaped with a mean of $41 and standard deviation of $6. Find the margin of error at a 90% confidence level.