The mean age of all 638 used cars for sale in the Washington Post one Saturday in 2013 was 7.9 years with a standard deviation of 7.7 years. The distribution of ages is right skewed. For a study to determine the reliability of classified ads, a reporter randomly selects 15 of these used cars and visits each owner to inspect the cars. He finds that the mean age of the 15 cars he samples is 8.2 years and the standard deviation of these 15 cars is 6.0 years.

14) In this example, the numerical values of 7.9 and 7.7 are:

a) Statistics.

b) Parameters.

c) Neither parameters nor statistics.

d) Both parameters and statistics.