The director of training for a company that manufactures electronic equipment is interested in determining whether different training methods have an effect on the productivity of assembly-line employees. She randomly assigns 21 of the 42 recently hired employees to a computer-assisted, individual-based training program. The other 21 are assigned to a team-based training program. Upon completion of the training, the employees are evaluated on the time (in seconds) it takes to assemble a part. The results are in the data file Training.
a. Using a 0.05 level of significance, is there evidence of a difference between the variances in assembly times (in seconds) of employees trained in a computer-assisted, individual-based program and those trained in a team based program?
b. On the basis of the results in (a), which t test defined in Section 10.1 should you use to compare the means of the two training programs? Discuss.