Sample of 100 agents
Agent ID	Years of Experience	Type of Experience	Performance ($1000)		The HR manager of a brokerage company is trying to find a model to predict their employees performances. They are planning to use Experience as an important potential predictor for the Annual Sale of their agents. This sheet includes information about "years of experience" and "type of the past occupation" for a sample of 100 agents working at the brokerage company.
1	1	Finance and Accounting	29
2	21	Sales	112
3	15	Operations	117
4	12	Finance and Accounting	82
5	19	Finance and Accounting	81		a) Draw a scatter chart showing the association between performance (Y) and years of experience (X) with different colors for different experience type levels. Please note you need to prepare ONE scatter chart with THREE separate data series.
6	6	Sales	84
7	23	Sales	89
8	6	Finance and Accounting	68		b) Define appropriate dummy variables to model "type of past experience" for regression purposes.
9	16	Sales	125
10	11	Finance and Accounting	93		c) Run a regression model to predict performance based on the two factors that measure experience (i.e., years of experience and type of experience). What is the equation? How much of the sample variation of agents performance does this model explain? Is years of experience a significant factor? How about the type of past experience? You first need to check the necessary conditions and comment on multicollinearity effect.
11	15	Sales	129
12	30	Sales	45
13	10	Operations	109
14	22	Sales	84
15	3	Sales	63		d) Run another regression model predicting performance based on type of past occupation, years of experience, and squared years of experience. What is the equation? Are necessary conditions of residuals satisfied?
16	20	Operations	121
17	30	Sales	32
18	8	Sales	111		e) Between these two models, which one would you prefer as your final choice? Why?
19	13	Operations	103
20	26	Sales	81
21	22	Operations	115
22	20	Operations	93
23	27	Sales	60
24	28	Operations	45
25	15	Operations	124
26	27	Finance and Accounting	90
27	2	Operations	48
28	1	Finance and Accounting	23
29	12	Sales	122
30	22	Sales	131
31	4	Sales	69
32	16	Sales	123
33	18	Sales	133
34	26	Sales	64
35	2	Finance and Accounting	37
36	12	Finance and Accounting	96
37	27	Sales	116
38	11	Operations	98
39	12	Finance and Accounting	79
40	29	Finance and Accounting	25
41	16	Operations	90
42	17	Sales	100
43	27	Operations	45