The following MINITAB output presents a $95 \%$ confidence interval.
$\begin{array}{crrcc}
\hline{\text { The assumed sigma }=9.9860} & \
\text { Variable } & \mathrm{N} & \text { Mean } & \text { SE Mean } & 95 \% \mathrm{CI} \
\mathrm{x} & 37 & 31.799 & 1.6417 & (28.581,35.017) \
\hline
\end{array}$

Use the appropriate critical value along with the information in the computer output to construct a $99 \%$ confidence interval.
A) (30.461, 33.137)
B) (28.581, 35.017)
C) (27.980, 35.618)
D) (27.570, 36.028)

Question

The following MINITAB output presents a $95 \%$ confidence interval.
$\begin{array}{crrcc}
\hline{\text { The assumed sigma }=9.9860} & \
\text { Variable } & \mathrm{N} & \text { Mean } & \text { SE Mean } & 95 \% \mathrm{CI} \
\mathrm{x} & 37 & 31.799 & 1.6417 & (28.581,35.017) \
\hline
\end{array}$

Use the appropriate critical value along with the information in the computer output to construct a $99 \%$ confidence interval.
A) (30.461, 33.137)
B) (28.581, 35.017)
C) (27.980, 35.618)
D) (27.570, 36.028)

Quizplus · Accepted Answer

The 99% confidence interval is wider than the 95% confidence interval. Using the standard error and the critical value for 99% confidence, the interval is calculated as (31.799 ± 2.576 * 1.6417), which results in (27.570, 36.028).

The Following MINITAB Output Presents A 95%95 \%95% Confidence Interval Use the Appropriate Critical Value Along with the Information in \begin{array}{crrcc}\hline{\text

The Following MINITAB Output Presents A $95 \%$ Confidence Interval Use the Appropriate Critical Value Along with the Information in \begin{array}{crrcc}
\hline{\text