Three different brands of magnetron tubes (the key

Chapter 15, Problem 31E

(choose chapter or problem)

Three different brands of magnetron tubes (the key components in microwave ovens) were

subjected to stressful testing, and the number of hours each operated without repair was recorded (see the accompanying table). Although these times do not represent typical life lengths, they do indicate how well the tubes can withstand extreme stress.

a Use the F test for a one-way layout (Chapter 13) to test the hypothesis that the mean length

of life under stress is the same for the three brands. Use \(\alpha=.05\). What assumptions are

necessary for the validity of this procedure? Is there any reason to doubt these assumptions?

b Use the Kruskal–Wallis test to determine whether evidence exists to conclude that the

brands of magnetron tubes tend to differ in length of life under stress. Test using \(\alpha=.05\).

Equation transcription:

Text transcription:

alpha=.05