The following MINITAB output presents a confidence interval for a population mean.
$\begin{array}{crrccc}
\hline \text { Variable } & \mathrm{N} & \text { Mean } & \text { StDev } & \text { SE Mean } & 99 \% \mathrm{CI} \
\mathrm{x} & 28 & 108.1268 & 30.4888 & 5.7618 & (92.161,124.093) \
\hline
\end{array}$
Use the information in the output to construct a $98 \%$ confidence interval.
A) (92.161, 124.093)
B) (105.235, 111.018)
C) (93.878, 122.376)
D) (105.546, 110.707)

Question

Quizplus · Accepted Answer

The 99% confidence interval is wider than the 98% confidence interval due to the higher confidence level requiring a larger margin of error. Since option C provides a range that is narrower than the 99% confidence interval but still reasonably wide, it is the correct choice. Options B and D are too narrow, and option A is the original 99% confidence interval.

The Following MINITAB Output Presents a Confidence Interval for a Population