answer 13.31

referende 13.30

13.30. Five measurements of the tar content of a certain kind of cigarette yielded 14.5, 14.2, 14.4, 14.3, and 14.6mg/cigarette. Assuming that the data are a random sample from a normal population, use the four steps on page 354 to show that at the 0.05 level of significance the null hypothesis =14.0 must be rejected in favor of the alternative =14.0. 13.31. With reference to Exercise 13.30, show that if the first measurement is recorded incorrectly as 16.0 instead of 14.5 , this will reverse the result. Explain the apparent paradox that even though the difference between the sample mean and 0 has increased, it is no longer significant