The average cost of a gallon of unleaded gasoline in Greater Cincinnati was reported to be $2.41 (The
Cincinnati Enquirer, February 3, 2006). During periods of rapidly changing prices, the newspaper
samples service stations and prepares reports on gasoline prices frequently. Assume the population
standard deviation is $0.15 for the price of a gallon of unleaded regular gasoline. What is the
necessary sample size the newspaper should use, with 95% confidence:
a) If the desired margin of error is $0.07
b) If the desired margin of error is $0.05
c) If the desired margin of error is $0.03
Cincinnati Enquirer, February 3, 2006). During periods of rapidly changing prices, the newspaper
samples service stations and prepares reports on gasoline prices frequently. Assume the population
standard deviation is $0.15 for the price of a gallon of unleaded regular gasoline. What is the
necessary sample size the newspaper should use, with 95% confidence:
a) If the desired margin of error is $0.07
b) If the desired margin of error is $0.05
c) If the desired margin of error is $0.03