Question 4: A certain airplane has two independent alternators to provide electrical power. The probability that a given alternator will fail on a

3,289

3,346

3,252

3,237

3,210

3,140

3,220

3,103

3,129

(a) Construct a 95 percent confidence interval for the true mean number of steps Dave takes on his run. (b) What sample size would be needed to obtain an error of ± 20 steps with 95 percent confidence?

(c) Using Excel, plot a line chart of the data. What do the data suggest about the pattern over time?