A research council wants to estimate the mean length of time (inminutes) that the average U.S. adult spends watching televisionusing digital video recorders (DVR’s) each day. To determine theestimate, the research council takes random samples of 35 U.S.adults and obtains the following times in minutes.
24 | 27 | 26 | 29 | 33 |
21 | 18 | 24 | 23 | 34 |
17 | 15 | 19 | 23 | 25 |
29 | 36 | 19 | 18 | 22 |
16 | 45 | 32 | 12 | 24 |
35 | 14 | 40 | 30 | 19 |
14 | 28 | 32 | 15 | 39 |
From past studies, the research council has found that thestandard deviation time is 4.3 minutes and that the population oftimes is normally distributed.
Construct a 90% confidence interval for the population mean.
Construct a 99% confidence interval for the population mean.
Interpret the results and compare the widths of the confidenceintervals.
Test the claim that the mean time spent watching DVR’s is 20minutes each day using a significance level of 0.05.
You may use Stat Disk, TI-84 calculator, or CrunchIt to find theconfidence intervals. Be sure to show your results in yourpost.