Answer to the following questions using the data set (Portfolio_hw). You can download this data set from Sogang cyber campus (1) Calculate sample correlation coefficient ( r ) for the returns between this year and last year using computer software (ex. MS-Excel: =correl). (2) Under the assumption that two variables (this year and last year returns) are from normal distributions, carry out test 0 H : 0 vs. 1 H : 0 at level 5%.

Last Year	This Year
11.9	15.4
19.5	26.7
11.2	18.2
14.1	16.7
14.2	13.2
5.2	16.4
20.7	21.1
11.3	12.0
-1.1	12.1
3.9	7.4
12.9	11.5
12.4	23.0
12.5	12.7
2.7	15.1
8.8	18.7
7.2	9.9
5.9	18.9