The Delldata.xlsx file contains monthly returns for the Standard & Poor’s stock index and for Dell stock. The beta of a stock is defined as the slope of the least-squares line used to predict the monthly return for a stock from the monthly return for the market.

		I used		slope	1.763768666
		paste special multiply to multiply		intercept	2.870068204
		numbers by 100.
Month#	Date	S and P return	Dell return	std error
1	1-Sep-88	4.2	28.21128451
2	1-Oct-88	2.7	15.82397004
3	1-Nov-88	-1.4	-8.407437348
4	1-Dec-88	1.8	-8.031774051
5	1-Jan-89	7.2	-4.990403071
6	1-Feb-89	-2.5	-17.17171717
7	1-Mar-89	2.4	-9.512195122
8	1-Apr-89	5.2	10.51212938
9	1-May-89	4	7.926829268
10	1-Jun-89	-0.5	-7.344632768
11	1-Jul-89	9	-14.26829268
12	1-Aug-89	1.9	3.698435277
13	1-Sep-89	-0.4	1.783264746
14	1-Oct-89	-2.3	-15.76819407
15	1-Nov-89	2.1	-4.16
16	1-Dec-89	2.4	-4.340567613		Forecast
17	1-Jan-90	-6.7	-15.88132635		Lower
18	1-Feb-90	1.3	35.06224066		Upper
19	1-Mar-90	2.6	21.96620584
20	1-Apr-90	-2.5	11.46095718
21	1-May-90	9.8	29.49152542
22	1-Jun-90	-0.7	14.7469459
23	1-Jul-90	-0.3	-6.920152091
24	1-Aug-90	-9	0
25	1-Sep-90	-4.9	-25.57189542
26	1-Oct-90	-0.4	21.51481888
27	1-Nov-90	6.4	23.48690154
28	1-Dec-90	2.7	40.96561814
29	1-Jan-91	4.4	22.31447846
30	1-Feb-91	7.2	11.58252015
31	1-Mar-91	2.4	12.88973384
32	1-Apr-91	0.3	-17.98585382
33	1-May-91	4.3	5.872689938
34	1-Jun-91	-4.6	-1.008533747
35	1-Jul-91	4.7	17.35893417
36	1-Aug-91	2.4	13.4557596
37	1-Sep-91	-1.6	2.324896998
38	1-Oct-91	1.3	-25.48173713
39	1-Nov-91	-4	-5.519104593
40	1-Dec-91	11.4	9.027777778
41	1-Jan-92	-1.9	24.39115774
42	1-Feb-92	1.3	9.427710843
43	1-Mar-92	-2	4.293971924
44	1-Apr-92	2.9	8.260754817
45	1-May-92	0.5	2.364700146
46	1-Jun-92	-1.5	-32.55537033
47	1-Jul-92	4	26.90677966
48	1-Aug-92	-2	9.766277129
49	1-Sep-92	1.2	13.38403042
50	1-Oct-92	0.4	19.20411357
51	1-Nov-92	3.4	7.689422356
52	1-Dec-92	1.3	30.61650993
53	1-Jan-93	0.7	-3.64
54	1-Feb-93	1.4	-30.53825931
55	1-Mar-93	2.2	9.322709163
56	1-Apr-93	-2.5	-17.43804665
57	1-May-93	2.7	-16.7954094
58	1-Jun-93	0.3	-22.28116711
59	1-Jul-93	-0.5	7.337883959
60	1-Aug-93	3.8	-8.712241653
61	1-Sep-93	-0.7	-9.508881923
62	1-Oct-93	2	21.78598922
63	1-Nov-93	-0.9	33.94437421
64	1-Dec-93	1.2	-16.58801321
65	1-Jan-94	3.4	-2.743988685
66	1-Feb-94	-2.7	13.61256545
67	1-Mar-94	-4.4	0.998463902
68	1-Apr-94	1.3	-12.85171103
69	1-May-94	1.6	30.10471204
70	1-Jun-94	-2.5	-7.869438855
71	1-Jul-94	3.3	6.163552536
72	1-Aug-94	4.1	16.06857143
73	1-Sep-94	-2.4	15.20283576
74	1-Oct-94	2.3	18.85470085
75	1-Nov-94	-3.7	-3.221630951
76	1-Dec-94	1.5	-4.800118888
77	1-Jan-95	2.6	3.965032782
78	1-Feb-95	3.9	-2.642642643
79	1-Mar-95	3	5.428747687
80	1-Apr-95	2.9	25.14628438
81	1-May-95	4	-7.995324372
82	1-Jun-95	2.4	19.36221573
83	1-Jul-95	3.3	8.10005322
84	1-Aug-95	0.3	18.46199291
85	1-Sep-95	4.2	10.38982628
86	1-Oct-95	-0.4	9.705594458
87	1-Nov-95	4.4	-5.092656143
88	1-Dec-95	1.9	-21.752965
89	1-Jan-96	3.4	-20.93345656
90	1-Feb-96	1	25.56399766
91	1-Mar-96	1	-2.541426178
92	1-Apr-96	1.5	36.93762537
93	1-May-96	2.6	20.71010045
94	1-Jun-96	0.4	-8.130598093
95	1-Jul-96	-4.5	9.095483709
96	1-Aug-96	2.1	20.94672509
97	1-Sep-96	5.6	15.82685799
98	1-Oct-96	2.7	4.663127135
99	1-Nov-96	7.6	24.88399528
100	1-Dec-96	-2	4.550034637
101	1-Jan-97	6.2	24.47068036
102	1-Feb-97	0.8	7.561459543
103	1-Mar-97	-4.2	-4.919802938
104	1-Apr-97	6	23.75195192
105	1-May-97	6.1	34.42691903
106	1-Jun-97	4.5	4.389008989
107	1-Jul-97	7.9	45.61023461
108	1-Aug-97	-5.6	-4.020584795
109	1-Sep-97	5.5	18.05065414
110	1-Oct-97	-3.3	-17.29069979
111	1-Nov-97	4.6	5.070090659
112	1-Dec-97	1.7	-0.222361594
113	1-Jan-98	1.1	18.37809524
114	1-Feb-98	7.2	40.66630731
115	1-Mar-98	5.1	-3.127931184
116	1-Apr-98	1	19.18819188
117	1-May-98	-1.7	2.05126935
118	1-Jun-98	4.1	12.62765999
119	1-Jul-98	-1.1	17.00333145
120	1-Aug-98	-14.5	-7.913541866
121	1-Sep-98	6.4	31.5
122	1-Oct-98	8.1	-0.380228137
123	1-Nov-98	6.1	-7.156641221
124	1-Dec-98	5.8	20.34979708
125	1-Jan-99	4.2	36.63516771
126	1-Feb-99	-3.1	-19.875
127	1-Mar-99	4	2.028081123
128	1-Apr-99	3.9	0.764525994
129	1-May-99	-2.4	-16.38846737
130	1-Jun-99	5.6	7.441016334
131	1-Jul-99	-3.1	10.47297297
132	1-Aug-99	-0.5	19.41896024
133	1-Sep-99	-2.7	-14.34058899
134	1-Oct-99	6.3	-4.035874439
135	1-Nov-99	2	7.165109034
136	1-Dec-99	5.9	18.60465116
137	1-Jan-00	-5	-24.63235294
138	1-Feb-00	-1.9	6.178861789
139	1-Mar-00	9.8	32.15926493
140	1-Apr-00	-3	-7.068366165
141	1-May-00	-2.1	-13.96508728
142	1-Jun-00	2.5	14.34782609
143	1-Jul-00	-1.6	-10.89987326
144	1-Aug-00	6.2	-0.711237553
145	1-Sep-00	-5.3	-29.36962751
146	1-Oct-00	-0.4	-4.259634888

Estimate the beta of Dell.