Kennebunkport, Maine, is a popular tourist town, but businesses suffer during the winter months, especially January. The mean hotel room occupation rate per day, a measure of tourist activity, is...

Kennebunkport, Maine, is a popular tourist town, but businesses suffer during the winter months, especially January. The mean hotel room occupation rate per day, a measure of tourist activity, is 23.1% during winter months. A new advertising campaign was launched to attract more tourists to this town during the winter. Following the campaign, a random sample of nine winter days was selected. The mean hotel room occupation rate was x = 24.6% and s = 2.1%. Is there any evidence to suggest the mean hotel room occupation rate has increased? Assume normality and use a = 0.01. If this test is significant, can you conclude the ad campaign caused the increase?

Economic growth in China has contributed to increased demand for crude oil and rising gasoline prices in several countries. In May 2013, the mean crude oil imported per day in China was 5.64 million barrels.40 A random sample of 17 days in the last quarter of 2013 was obtained and the crude oil imported was recorded for each (in million barrels per day, bpd). The summary statistics were x = 5.869 million bpd and s = 1.16 million bpd. Is there any evidence to suggest that the mean crude oil imported per day in China has increased? Use a = 0.05 and assume normality.