The following MINITAB output display presents a 95% confidence interval for the difference between two means. $\begin{array}{rrrrc}
& \mathrm{N} & \text { Mean } & \text { StDev } & \text { SE Mean } \
\mathrm{A} & 9 & 55.539 & 23.660 & 7.887 \
\mathrm{~B} & 7 & 89.948 & 25.488 & 9.634
\end{array}$

$\text { What is the point estimate of } \mu _ { 1 } - \mu _ { 2 } ?$
A) -34.409
B) 89.948
C) 13
D) -48.804

Question

The following MINITAB output display presents a 95% confidence interval for the difference between two means. $\begin{array}{rrrrc} 
& \mathrm{N} & \text { Mean } & \text { StDev } & \text { SE Mean } \
\mathrm{A} & 9 & 55.539 & 23.660 & 7.887 \
\mathrm{~B} & 7 & 89.948 & 25.488 & 9.634
\end{array}$

$\text { What is the point estimate of } \mu _ { 1 } - \mu _ { 2 } ?$
A) -34.409 
B) 89.948 
C) 13 
D) -48.804

Quizplus · Accepted Answer

The point estimate of $\mu_1-\mu_2$ is the difference between the sample means:

$\bar{x}_1-\bar{x}_2=55.539-89.948=-34.409$

Therefore, the best choice is A.

The Following MINITAB Output Display Presents a 95% Confidence Interval