Colvard Office Products, a national producer and supplier of a line of office furniture products, including desks, chairs, bookcases, and filing cabinets, currently employs a sales force of 240 scattered across the United States. Richard Garrett, the vice president of marketing, has the primary responsibility for Colvard's sales and product distribution.

Each year, Colvard hires approximately 20-40 new salespeople, who are put through the company's excellent one-week sales training program. At the conclusion of the training program, they take a four-hour written test that measures what the employee has learned and also contains a section on general knowledge and a section designed to capture information about the employee's personality and character traits. A total score is produced along with three subscores.

After their first year of employment with Colvart, the new sales employees are evaluated by their regional sales managers, who submit performance ratings, based on a scale from 0 to 100, to Richard Garrett. Over the years, Garrett has noted that these performance ratings are highly correlated with the total score from the post-training test, and he has used the test results as an "early performance indicator" for new hires.

The personnel office at Colvard wants to cut costs by reducing the length of the four-hour sales training test. Garrett has been asked for his opinion about the value of the test and whether it would be reasonable to eliminate portions of it. His initial reaction was that the test was a proven indicator of future sales performance and that it should be continued as is, but he agreed to investigate whether a subset of the test might serve just as well.

Garrett had never before examined the relationship of the three individual subscores to sales performance. He was not sure how to predict sales performance from a subset of the three subscores or how to assess their predictive ability.

Garrett has provided you with a database containing total test scores and subscores for the most recent 120 salespeople hired along with their individual sales ratings after one year on the job. The following are the variables (and their definitions) contained in the database:

Rating	Sales performance rating for first year on the job
SubScore1	Subscore on the first section of the test
SubScore2	Subscore on the second section of the test
SubScore3	Subscore on the third section of the test
TotalScore	Total of the three subscores of the test

Garrett wants you to determine which subscores, alone or in combination, provide the best prediction of sales performance at the end of the first year. He also wants you to compare this approach to using just the total score and recommend how he should respond to the personnel office's request to shorten the test.

Write a one-page memo to Garrett that briefly summarizes the results of your analysis and recommendation. Keep in mind that Garrett is not familiar with any statistical jargon, so make sure you write the memo without it.

	SubScore1	SubScore2	SubScore3	TotalScore
75	50	51	54	155
56	40	34	45	119
86	48	56	64	168
63	46	43	51	140
80	50	57	56	163
63	45	46	49	140
61	44	59	56	159
66	48	49	53	150
61	43	38	42	123
45	30	29	41	100
43	43	37	31	111
50	55	46	45	146
56	40	50	43	133
68	47	50	48	145
47	39	47	40	126
54	46	42	46	134
80	49	67	59	175
63	52	48	44	144
43	24	28	38	90
77	59	65	59	183
86	47	46	55	148
70	59	60	46	165
66	62	55	33	150
84	71	63	59	193
52	44	42	47	133
59	42	40	49	131
75	48	57	57	162
61	40	42	49	131
61	46	44	45	135
52	51	54	38	143
98	63	64	77	204
61	46	50	38	134
86	58	53	54	165
52	46	45	39	130
52	44	42	42	128
77	60	71	62	193
75	50	58	58	166
75	53	51	51	155
73	47	46	59	152
59	76	76	33	185
73	59	49	57	165
70	64	54	54	172
75	49	49	53	151
77	58	57	51	166
68	38	38	64	140
54	49	56	36	141
73	46	32	55	133
54	43	49	40	132
75	71	58	50	179
52	45	49	56	150
47	42	40	46	128
66	56	59	46	161
45	45	58	44	147
93	62	68	60	190
77	69	66	49	184
98	74	73	57	204
68	58	56	50	164
61	46	35	53	134
80	58	55	55	168
47	51	48	37	136
54	46	41	43	130
93	65	71	64	200
66	43	48	51	142
80	72	73	54	199
75	52	48	52	152
50	48	47	42	137
61	56	47	42	145
86	54	53	60	167
50	44	40	33	117
82	61	72	63	196
75	51	66	53	170
52	33	37	40	110
38	34	34	27	95
54	37	30	35	102
47	35	40	46	121
86	62	60	64	186
56	45	46	54	145
68	46	52	55	153
59	46	60	48	154
56	34	35	53	122
45	44	38	40	122
68	66	57	47	170
63	40	34	54	128
47	57	54	36	147
75	60	58	54	172
66	44	47	60	151
89	58	55	64	177
73	52	54	51	157
75	47	58	61	166
59	50	50	50	150
66	62	60	50	172
47	45	38	36	119
54	64	55	36	155
68	52	42	56	150
91	56	65	65	186
56	59	52	49	160
61	59	59	44	162
96	63	66	64	193
63	48	45	47	140
75	60	70	51	181
54	47	56	53	156
96	59	66	72	197
59	59	53	33	145
93	57	54	68	179
56	47	50	53	150
61	45	28	54	127
59	51	38	48	137
54	50	43	44	137
84	65	65	49	179
40	38	43	32	113
93	50	56	64	170
73	50	53	64	167
70	59	56	58	173
63	38	46	51	135
73	39	44	58	141
59	50	48	45	143
66	54	54	41	149
63	55	46	50	151
54	43	39	38	120
54	47	44	50	141