1. It is claimed that two of three Americans say that the chances of world peace are seriously threatened by the nuclear capabilities of other countries. If in a random sample of 400 Americans, it is found that only 252 hold this view, do you think the claim is correct? Use α = 0.05. State any assumptions you make in solving this problem.

2. According to the Bureau of Labor Statistics (1996), the average price of a gallon of gasoline in all U.S. cities in the United States in January 1996 was $1.129. A later random sample in 24 cities found the mean price to be $1.24 with a standard deviation of 0.01. Test at α = 0.05 to see whether the average price of a gallon of gas in the cities had recently changed.