The price per share of stock for a sample of 20 companies was recorded at the beginning of 2012 and then again at the end of the 1st quarter of 2012. How stocks perform during the 1st quarter is an indicator of what is ahead for the stock market and the economy. Use the sample data in the table below to answer the following. End of 1st Begining of Company Quarter Year Kraft Foods 38.01 37.36 Dupont 52.90 45.78 Consolidated Edison 58.42 62.03 Johnson & Johnson 65.96 65.58 Union Pacific 107.48 105.94 Comcast 30.01 23.71 Pfiser 43.41 41.22 AT&T 31.23 30.24 Cisco Systems 21.15 18.08 Home Depot 50.31 42.04 JP Morgan Chase 45.98 33.25 Procter & Gamble 67.21 66.71 38.23 Verizon 40.12 Devon Energy 71.12 62.00 32.26 Microsoft 25.96 74.01 69.97 68.06 54.70 86.73 84.76 29.16 25.58 107.21 106.40 Coco Cola Qualcomm Exxon Mobil Oracle Systems Chevron a. Let d; denote the change in price per share for company i where d; = end of 1st quarter of 2012 price per share minus the beginning of 2012 price per share. Use the sample mean of these values to estimate the dollar amount a share of stock has changed during the 1st quarter.