Chapter 6.2, Problem 20E

Gasoline Prices. Suppose that the average price for a gallon of gasoline in the United States is $3.73 and in Russia is $3.40. Assume these averages are the population means in the two countries and that the probability distributions are normally distributed with a standard deviation of $.25 in the United States and a standard deviation of $.20 in Russia.

1. a. What is the probability that a randomly selected gas station in the United States charges less than $3.50 per gallon?
2. b. What percentage of the gas stations in Russia charge less than $3.50 per gallon?
3. c. What is the probability that a randomly selected gas station in Russia charged more than the mean price in the United States?