Test for the correlation

Do stock prices of competing companies move together? Below are daily closing prices of two computer services firms, IBM = International Business Machines Corporation, HPQ = Hewlett-Packard Company.

a) Calculate the sample correlation coefficient using technology (e.g. Excel).

b) Atcan you conclude that the true correlation coefficient is not equal to zero?

A1 V X V fx B C D E F G H K M N O P Q R S U V W A Daily Closing Closing Prices of Two Stocks Date IBM HPQ 3/1/11 159.26 42.83 Learning Stats 3/2/11 159.45 43.16 Copyright @ 2019 3/3/11 162.75 43.12 by 3/4/11 161.11 42.53 The McGraw-Hill Companies 3/7/11 159.22 41.90 This spreadsheet is intended solely 3/8/11 161.56 42.32 for educational purposes by 3/9/11 165.12 41.97 licensed users of Connect 3/10/11 161.30 41.40 3/11/11 161.71 41.65 3/14/11 160.67 41.49 Source: finance.yahoo.com 3/15/11 158.31 40.93 3/16/11 152.32 40.14 3/17/11 153.49 41.43 3/18/11 155.20 41.32 3/21/11 156.98 41.77 3/22/11 157.30 41.74 3/23/11 158.82 42.07 3/24/11 159.33 43.10 3/25/11 161.46 42.53 3/28/11 160.65 42.14 3/29/11 162.15 41.11 3/30/11 162.87 41.30 26 3/31/11 162.34 40.97 27 4/1/11 163.54 40.98 28 4/4/11 63.52 40.34 Data Extra Sheet +A1 XV fx B C D E G H K M N O P Q R S U V WA 3/25/11 161.46 42.53 3/28/11 160.65 42.14 3/29/11 162.15 41.11 3/30/11 162.87 41.30 3/31/11 162.34 40.97 4/1/11 163.54 40.98 4/4/11 163.52 40.34 4/5/11 163.26 40.29 30 4/6/11 163.31 41.18 31 4/7/11 163.65 41.08 32 4/8/11 163.32 40.70 33 4/11/11 163.22 41.05 34 4/12/11 162.52 41.08 35 4/13/11 163.22 41.13 4/14/11 164.24 40.36 4/15/11 165.47 40.26 38 4/18/11 165.20 39.75 4/19/11 164.66 39.99 4/20/1 1 164.02 40.89 4/21/11 167.53 40.99 4/25/11 166.92 40.53 4/26/11 167.74 40.69 4/27/11 169.61 41.04 4/28/11 170.02 40.53 4/29/11 169.82 40.37 49 Data Extra Sheet +