In January 2011, the United States Saw an Increase in Gas

Multiple Choice

In January 2011, the United States saw an increase in gas prices.Imagine the average price per gallon was $3.12 with a standard deviation of $0.27, according to a source such as AAA (Automobile Association of America) that tracks gas prices.Adam is on his long mid-semester break, so he and some of his friends decide to go on a 3000-mile road trip.He records the price of gas each of the 10 times they fill up the tank, and he computes an average price per gallon of $3.16.What percent of other sample means, based on 10 gas stations, would be greater than the one Adam observed? (Round z score to two decimal places.)

A) 19.85
B) 31.92
C) 69.85
D) 80.15