Question: 52: Dave the jogger runs the same route every day (about 2.2 miles). On 18 consecutive days, he

recorded the number of steps using a pedometer. The results were

3,450 3,363 3,228 3,360 3,304 3,407 3,324 3,365 3,290

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 does the data suggest about the pattern over time?