csat-suneung 2006 Q14

csat-suneung · South-Korea · csat__math-science 3 marks Normal Distribution Sampling Distribution of the Mean
The weight of products manufactured at a certain factory follows a normal distribution $\mathrm { N } \left( 11,2 ^ { 2 } \right)$. Two people A and B each independently randomly extracted a sample of size 4. Using the standard normal distribution table on the right, what is the probability that the sample means of both A and B are between 10 and 14 inclusive? [3 points]
$z$$\mathrm { P } ( 0 \leqq Z \leqq z )$
10.3413
20.4772
30.4987

(1) 0.8123
(2) 0.7056
(3) 0.6587
(4) 0.5228
(5) 0.2944
The weight of products manufactured at a certain factory follows a normal distribution $\mathrm { N } \left( 11,2 ^ { 2 } \right)$. Two people A and B each independently randomly extracted a sample of size 4. Using the standard normal distribution table on the right, what is the probability that the sample means of both A and B are between 10 and 14 inclusive? [3 points]

\begin{center}
\begin{tabular}{ | c | c | }
\hline
$z$ & $\mathrm { P } ( 0 \leqq Z \leqq z )$ \\
\hline
1 & 0.3413 \\
2 & 0.4772 \\
3 & 0.4987 \\
\hline
\end{tabular}
\end{center}

(1) 0.8123\\
(2) 0.7056\\
(3) 0.6587\\
(4) 0.5228\\
(5) 0.2944