Can the main effect of machine on the number of parts produced be interpreted? If so, interpret the main effect, using the

α = 0.05 level of significance. If not, explain why not.

Exercises 5–7 refer to the following data:
A machine shop has four machines used in precision grinding of bearings. Three machinists are employed to grind bearings on the machines. In an experiment to determine whether there are differences in output among the operators or the machines, each operator worked on each machine for three days. The response variable was the number of parts produced. The results are presented in the following table.

Transcribed Image Text:

Machine 1 Machine 2 Operator A 38 33 20 40 43 47 43 31 40 Machine 3 Machine 4 40 38 39 Operator B Operator C 33 34 34 39 37 47 35 43 31 36 46 46 28 34 40 49 36 50 39 37 35 34 39 38