PepsiCo Stock Volume The trade volume of a stock is the number of shares traded on a

Chapter 9, Problem 40

(choose chapter or problem)

PepsiCo Stock Volume The trade volume of a stock is the number of shares traded on a given day. The following data, in millions (so that 6.16 represents 6,160,000 shares traded), represent the volume of PepsiCo stock traded for a random sample of 40 trading days in 2010. 6.16 6.39 5.05 4.41 4.16 4.00 2.37 7.71 4.98 4.02 4.95 4.97 7.54 6.22 4.84 7.29 5.55 4.35 4.42 5.07 8.88 4.64 4.13 3.94 4.28 6.69 3.25 4.80 7.56 6.96 6.67 5.04 7.28 5.32 4.92 6.92 6.10 6.71 6.23 2.42 Source: TD Ameritrade (a) Use the data to compute a point estimate for the population mean number of shares traded per day in 2010. (b) Construct a 95% confidence interval for the population mean number of shares traded per day in 2010. Interpret the confidence interval. (c) A second random sample of 40 days in 2010 resulted in the data shown next. Construct another 95% confidence interval for the population mean number of shares traded per day in 2010. Interpret the confidence interval. 6.12 5.73 6.85 5.00 4.89 3.79 5.75 6.04 4.49 6.34 5.90 5.44 10.96 4.54 5.46 6.58 8.57 3.65 4.52 7.76 5.27 4.85 4.81 6.74 3.65 4.80 3.39 5.99 7.65 8.13 6.69 4.37 6.89 5.08 8.37 5.68 4.96 5.14 7.84 3.71 (d) Explain why the confidence intervals obtained in parts (b) and (c) are different.