1. In 1990, the average duration of long-distance telephone calls originating in one town was 7.2 minutes. A long-distance telephone company wants to perform a hypothesis test to determine whether the average duration of long-distance phone calls has changed from the 1990 mean of 7.2 minutes. Write the null and alternative hypothesis.

2. A skeptical paranormal researcher claims that the proportion of Americans that have seen a UFO, p, is less than 5 in every one thousand. Write the null and alternative hypothesis.

3. A medical school claims that more than 28% of its students plan to go into general practice. It is found that among a random sample of 130 of the school's students, 39% of them plan to go into general practice. Find the P-Value for a test of the school's claim.

4. In a sample of 88 children selected randomly from one town, it is found that 8 of them suffer from asthma. Find the P-value for a test of the claim that the proportion of all children in the town who suffer from asthma is equal to 11%.

5. Test the claim that the mean age of the prison population in one city is less than 26 years. Sample data are summarized as n = 25, x = 24.4 years, and s = 9.2 years. Use a significance level of α = 0.05.

Find the test statistic t.