A travel company is investigating whether the average cost of a hotel stay in a certain city has increased over the past year. The company recorded the cost of a one-night stay for a Friday night in January of the current year and in the previous year for 31 hotels selected at random. The difference in cost (current year minus previous year) was calculated for each hotel.
Which of the following is the appropriate test for the company’s investigation?
A one-sample z
-test for a population mean
A
A one-sample t
-test for a sample mean
B
A one-sample z
-test for a population proportion
C
A matched-pairs t
-test for a mean difference
D
A two-sample t
-test for a difference between means
E
Is it a matched pair t test for mean difference so D?