Question

The production manager of High Point Sofa and Chair, a large furniture manufacturer located in North Carolina, is studying the job performance ratings of a sample of 15 electrical repairmen employed by the company. An aptitude test is required by the human resources department to become an electrical repairman. The production manager was able to get the score for each repairman in the sample. In addition, he determined which of the repairmen were union members (code = 1) and which were not (code = 0). The sample information is reported below.

Worker	Job Performance Score		Aptitude Test Score		Union Membership
Abbott	58		5		0
Anderson	53		4		0
Bender	33		10		0
Bush	97		10		0
Center	36		2		0
Coombs	83		7		0
Eckstine	67		6		0
Gloss	84		9		0
Herd	98		9		1
Householder	45		2		1
Iori	97		8		1
Lindstrom	90		6		1
Mason	96		7		1
Pierse	66		3		1
Rohde	82		6		1

a) By how much does the membership in a particular union increase the typical performance?

b) Test at the .05 significance level whether the union variable is significant. For full credit, show the four steps (hypothesis, test statistic, critical value rejection rule, p-value rejection rule, decision and interpret).

c) Conduct a joint test of significance to see if any of the set of regression coefficients could be different from zero. Use the .05 significance level. For full credit, show the four steps (hypothesis, test statistic, critical value rejection rule, p-value rejection rule, decision and interpret).

Answer 1