Refer to Exercise 14.33. Suppose that the two laboratories were randomly selected from a population of laboratories for participation in the study, which also included time as a possible source of variability.
a. Obtain the expected mean squares for all sources of variability.
b. Test all relevant sources of variability for significance. Use α = .05.
c. Compare the results obtained here to the results obtained in Exercise 14.34.
d. Does considering the laboratory effects to be random effects seem more relevant than considering them to be fixed effects? Explain your answer.