5.

A fitness center is interested in finding a 90% confidence interval for the mean number of days per week that Americans who are members of a fitness club go to their fitness center. Records of 220 members were looked at and their mean number of visits per week was 2.4 and the standard deviation was 2.1.

Round your answers to two decimal places.

A. The sampling distribution follows adistribution.

B. With 90% confidence the population mean number of visits per week is betweenandvisits.

C. If many groups of 220 randomly selected members are studied, then a different confidence interval would be produced from each group. Aboutpercent of these confidence intervals will contain the true population mean number of visits per week and aboutpercent will not contain the true population mean number of visits per week.

6.

The mayor is interested in finding a 95% confidence interval for the mean number of pounds of trash per person per week that is generated in city. The study included 120 residents whose mean number of pounds of trash generated per person per week was 31.5 pounds and the standard deviation was 7.8 pounds.

Round your answers to two decimal places.

A. The sampling distribution follows adistribution.

B. With 95% confidence the population mean number of pounds per person per week is betweenandpounds.

C. If many groups of 120 randomly selected people in the city are studied, then a different confidence interval would be produced from each group. Aboutpercent of these confidence intervals will contain the true population mean number of pounds of trash generated per person per week and aboutpercent will not contain the true population mean number of pounds of trash generated per person per week.

7.

You are interested in finding a 95% confidence interval for the average commute that non-residential students have to their college. The data below show the number of commute miles for 18 randomly selected non-residential college students.

4,10,16,0,24,1,15,16,7,20,7,3,0,2,19,23,10,18

Assume a normal distribution and round your answers to two decimal places.

A. The sampling distribution follows adistribution.

B. With 95% confidence the mean commute for non-residential college students is betweenandmiles.

C. If many groups of 18 randomly selected non-residential college students are surveyed, then a different confidence interval would be produced from each group. Aboutpercent of these confidence intervals will contain the true population mean number of commute miles and aboutpercent will not contain the true population mean number of commute miles.

8.

The standard deviation for the number of times per year single people go on date is known to be 18.3. You are interested in finding a 95% confidence interval for the average dates per year that single college students go on. The data below show the results of the survey that you took.Assume the standard deviation for single college students is the same as the standard deviation for single people in general.

5,8,12,45,0,23,17,4,6,9,16

Assume a normal distribution and round your answers to two decimal places.

A. The sampling distribution follows adistribution.

B. With 95% confidence the mean number of dates that single college students have each year is betweenand.

C. If many groups of 11 randomly selected single college students are surveyed, then a different confidence interval would be produced from each group. Aboutpercent of these confidence intervals will contain the true population mean dates per year and aboutpercent will not contain the true population mean dates per year.