Question

The accompanying data represent the total travel tax​ (in dollars) for a​ 3-day business trip in 8 randomly selected cities. A normal probability plot suggests the data could come from a population that is normally distributed. A boxplot indicates there are no outliers. Complete parts​ (a) through​ (c) below.

68.75 79.27 69.24 84.12 80.78 86.19 100.66 99.24

​(a) Determine a point estimate for the population mean travel tax. A point estimate for the population mean travel tax is $____ ​(Round to two decimal places as​ needed.)

​(b) Construct and interpret a 95​% confidence interval for the mean tax paid for a​ three-day business trip. Select the correct choice below and fill in the answer boxes to complete your choice. ​(Round to two decimal places as​ needed.)

A. One can be ____% confident that the all cities have a travel tax between ​$____ and ​$____.

B. One can be ____% confident that the mean travel tax for all cities is between ​$____and $____.

C. The travel tax is between ​$____ and $____ for ____%of all cities.

D. There is a ___​% probability that the mean travel tax for all cities is between ​$____ and $____. ​

(c) What would you recommend to a researcher who wants to increase the precision of the​ interval, but does not have access to additional​ data?

A. The researcher could increase the level of confidence.

B. The researcher could decrease the level of confidence.

C. The researcher could increase the sample mean.

D. The researcher could decrease the sample standard deviation.

Answer 1