The club professional at a difficult public course boasts that his course is so tough that the average golfer loses a dozen or more golf balls during a round of golf. a dubious golfer sets out to show that the pro is fibbing. he asks a random sample of 15 golfers who just completed their rounds to report the number of golf balls each lost. assuming that the number of golf balls lost is normally distributed with a standard deviation of 3. write down the null and the alternative hypothesis. using p-value approach only, can we infer at the 10% significance level that the average number of golf balls lost is less than 12? from the evidence, do you reject the null hypothesis? (hint: the sample mean is 11.)

1 14 8 15 17 10 4
12 6 14 21 15 9 11 8