A cigarette manufacturer has advertised that it has developed a new brand of cigarette,...

A cigarette manufacturer has advertised that it has developed a new brand of cigarette, LowTar, that has a lower average tar content than the major brands. To evaluate this claim, a consumer testing agency randomly selected 100 cigarettes from each of the four leading brands of cigarettes and 100 from the new brand. The tar content (milligrams) of the cigarettes gave the following results:

A boxplot of the data used to produce the table are given here.

a. Based on the information contained in the boxplot, does the LowTar brand appear to have a lower average tar content than the other brands?

b. Using the computer output shown here, is there a significant (α = .01 ) difference in the average tar content of the five brands of cigarettes?

c. What is the p-value of the test statistic in (b)?

d. What are the practical consequences of making a Type I error with respect to your test in (b)?