The two samples whose statistics are given in the table are thought to come from populations with
Equal variances. What is the pooled estimate of the population standard deviation? $$\begin{array} { | c | c | c | }
\hline n & \text { Mean } & \text { SD } \
\hline 25 & 32 & 5 \
\hline 20 & 30 & 6 \
\hline
\end{array}$$
A) 5.46
B) 1.64
C) 5.50
D) 5.59
E) 3.32

Question

The two samples whose statistics are given in the table are thought to come from populations with
Equal variances. What is the pooled estimate of the population standard deviation? $$\begin{array} { | c | c | c | } 
\hline n & \text { Mean } & \text { SD } \
\hline 25 & 32 & 5 \
\hline 20 & 30 & 6 \
\hline
\end{array}$$
A) 5.46
B) 1.64
C) 5.50
D) 5.59
E) 3.32

Quizplus · Accepted Answer

The pooled estimate of the population standard deviation is calculated using the formula: $\sqrt{\frac{(n_1-1)s_1^2 + (n_2-1)s_2^2}{n_1+n_2-2}}$. Substituting the given values: $\sqrt{\frac{(25-1)5^2 + (20-1)6^2}{25+20-2}} = 5.46$.

The Two Samples Whose Statistics Are Given in the Table n Mean SD 2532520306\begin{array} { | c | c | c | } \hline n & \text { Mean } & \text { SD } \\\hline 25 & 32 & 5 \\\hline 20 & 30 & 6 \\\hline\end{array}n2520​ Mean 3230​ SD 56​​

The Two Samples Whose Statistics Are Given in the Table $\begin{array} { | c | c | c | } \hline n & \text { Mean } & \text { SD } \\\hline 25 & 32 & 5 \\\hline 20 & 30 & 6 \\\hline\end{array}$