90% confidence interval: (0.2742,0.3058)

95% confidence interval: (0.2712,0.3088)

95% confidence interval: (0.2712,0.3088)

Question

asked 2021-05-26

Construct 90% and 95% confidence intervals for the population proportion. Interpret the results and compare the widths of the confidence intervals. In a survey of 2241 U.S. adults in a recent year, 1322 say they have made a New Year's resolution.

asked 2021-06-20

Use the information to construct 90% and 99% confidence intervals for the population mean. Interpret the results and compare the widths of the confidence intervals. A group of researchers estimates the mean length of time (in minutes) the average U.S. adult spends watching television using digital video recorders (DVRs) and other forms of time-shifted television each day. To do so, the group takes a random sample of 30 U.S. adults and obtains the times (in minutes) below.
29 12 23 24 33 24 28 31 18 27 27 32 17 13 17 12 21 32 26 16 28 28 21 24 29 13 20 13 21 27
From past studies, the research council assumes that σσ is 6.5 minutes.

asked 2021-06-23

Let p be the population proportion for the situation. (a) Find point estimates of p and q, (b) construct 90% and 95% confidence intervals for p, and (c) interpret the results of part (b) and compare the widths of the confidence intervals. In a survey of 1035 U.S. adults, 745 say they want the U.S. to play a leading or major role in global affairs.

asked 2021-06-16

Let p be the population proportion for the situation. (a) Find point estimates of p and q, (b) construct 90% and 95% confidence intervals for p, and (c) interpret the results of part (b) and compare the widths of the confidence intervals. In a survey of 2202 U.S. adults, 1167 think antibiotics are effective against viral infections.