Question: Tennis Fans. The Tennis Industry Association stated that the average age of a tennis fan is 32 years. To test the claim, a researcher selected a random sample of 18 tennis fans and found that the mean of their ages was 31.3 years and the standard deviation was 2.8 years. At a = 0.05 does it appear that the average age is lower than what was stated by the Tennis Industry Association? Use the P-value method, and assume the variable is approximately normally distributed.