The price per share of stock for a sample of 25 companies was recorded at the beginning of the first financial quarter and then again at the end of the first financial quarter. How stocks perform during the first financial quarter is an indicator of what is ahead for the stock market and the economy. Company End of 1st quarter Beginning of 1st quarter
Bank of New York Mellon 54.19 53.82
Kraft Foods 55.70 77.02
E. I. du Pont de Nemours and Company 102.57 109.00
Consolidated Edison 79.95 83.58
Johnson & Johnson 126.01 139.23
Union Pacific 132.73 135.78
Comcast 32.06 41.07
Applied Materials 50.91 53.04
Pfizer 35.40 36.44
General Electric 14.05 17.98
AT&T 32.54 38.54
Cisco Systems 44.83 38.86
Home Depot 184.63 188.03
JP Morgan Chase 108.78 107.95
Procter & Gamble 71.96 90.65
Verizon 48.82 53.53
Devon Energy 36.20 42.23
Lilly 79.07 84.68
Microsoft 95.00 85.95
Coca Cola 42.59 45.59
Qualcomm 50.82 65.20
Exxon Mobil Corporation 76.95 85.03
PG&E Corporation 46.27 44.49
Oracle Corporation 45.95 46.63
Chevron 129.86 127.58
(a) Let di denote the percentage change in price per share for company i where
di =
end of 1st quarter price per share − beginning of 1st quarter price per share
beginning of 1st quarter price per share
 Use the sample mean of these values to estimate the percentage change in the stock price over the first quarter. (Round your answer to one decimal place.)
%
(b) What is the 95% confidence interval estimate of the population mean percentage change in the price per share of stock during the first quarter? (Round your answers to one decimal place.)
% to %
Interpret this result.
Because the 95% confidence interval ---Select--- (contains is completely above is completely below) zero, we can be 95% confident that the population mean percentage change in the price per share of stock ---Select--- (is positive is negative may be zero )