1. Calculate the correlation between the columns of data below (Y, X1, X2) .
2. What do these correlations tell you about the relationships between (Y and X1) (X1 and X2) and (Y and X2)?
3. Using the Data Analysis Add-In in excel, run a regression to explain the variable Y with the other two variables.
4. According to this regression, do either X1 or X2 or both help to explain the variable Y? Is that help significant/useful?

#	Y	X1	X2
1	-0.4	1.5	20.7
2	-1.7	3.8	20.3
3	-0.3	3.3	18.5
4	-0.7	5.0	17.7
5	-2.1	6.6	16.6
6	-0.2	7.2	16.7
7	-0.6	8.3	14.9
8	-5.4	8.7	13.7
9	-7.1	10.2	13.5
10	-9.9	11.7	12.2
11	-6.9	12.2	11.0
12	-6.5	12.1	9.6
13	-11.2	13.7	8.8
14	-5.0	14.8	7.0
15	-5.0	16.8	7.5
16	-1.9	17.6	5.1
17	-10.7	17.1	5.8
18	-0.4	19.8	4.5
19	-16.9	20.3	3.8
20	-15.4	21.0	2.5