$$\begin{array}{l}
\text { In testing the equality of the two means below, what is the test statistic? (Use the equal variances }\
\begin{array} { | l | c | c | }
\hline & \text { Sample 1 } & \text { Sample 2 } \
\hline \text { Sample size } & 12 & 9 \
\hline \text { Sample mean } & 115 & 80 \
\hline \text { Sample variance } & 700 & 400 \
\hline
\end{array}
\end{array}$$
A) 3.31
B) 1.75
C) 0.31
D) 2.31

Question

$$\begin{array}{l}
\text { In testing the equality of the two means below, what is the test statistic? (Use the equal variances }\
\begin{array} { | l | c | c | } 
\hline & \text { Sample 1 } & \text { Sample 2 } \
\hline \text { Sample size } & 12 & 9 \
\hline \text { Sample mean } & 115 & 80 \
\hline \text { Sample variance } & 700 & 400 \
\hline
\end{array}
\end{array}$$
A) 3.31
B) 1.75
C) 0.31
D) 2.31

Quizplus · Accepted Answer

The test statistic for testing the equality of the two means is the z-statistic, which is calculated as follows:z = (x1 - x2) / sqrt(s1^2/n1 + s2^2/n2)where x1 and x2 are the sample means, s1 and s2 are the sample standard deviations, and n1 and n2 are the sample sizes.In this case, the z-statistic is calculated as follows:z = (115 - 80) / sqrt(700^2/12 + 400^2/9) = 3.31Therefore, the correct answer is A) 3.31.

A) 331 B) 1

A) 331
B) 1