The average price for a gallon of gasoline is $3.73 in the United States and $3.40 in Russia (Bloomberg Business week, March 5–March 11, 2012). 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.

a. What is the probability that a randomly selected gas station in the United States charges less than $3.50 per gallon?

b. What percentage of the gas stations in Russia charge less than $3.50 per gallon?

c. What is the probability that a randomly selected gas station in Russia charges more than the mean price in the United States?