Questions: Assume that the sample is a simple random sample obtained from a normally distributed population of IQ scores of statistics professors. Use the table below to find the minimum sample size needed to be 99% confident that the sample standard deviation s is within 40% of σ. Is this sample size practical? * To be 95% confident that s is within 1% 5% 10% 20% 30% 40% 50% * of the value of σ, the sample size n should be at least 19,205 768 192 48 21 12 8 * To be 99% confident that s is within 1% 5% 10% 20% 30% 40% 50% * of the value of σ, the sample size n should be at least 33,218 1,336 336 85 38 22 14 The minimum sample size needed is . Is this sample size practical? A. No, because the sample size is excessively large to be practical for most applications. B. No, because the sample size should be as small as possible for most applications. C. Yes, because the sample size should be as large as possible for most applications. D. Yes, because the sample size is small enough to be practical for most applications.

Transcript text: Assume that the sample is a simple random sample obtained from a normally distributed population of IQ scores of statistics professors. Use the table below to find the minimum sample size needed to be $99 \%$ confident that the sample standard deviation s is within $40 \%$ of $\sigma$. Is this sample size practical? \begin{tabular}{|c|c|c|c|c|c|c|c|c|} \hline \multirow{4}{*}{*} & To be $95 \%$ confident that s is within & $1 \%$ & $5 \%$ & $10 \%$ & $20 \%$ & $30 \%$ & $40 \%$ & $50 \%$ \\ \hline & of the value of $\sigma$, the sample size n should be at least & 19,205 & 768 & 192 & 48 & 21 & 12 & 8 \\ \hline & To be 99\% confident that s is within & $1 \%$ & $5 \%$ & $10 \%$ & 20\% & $30 \%$ & $40 \%$ & $50 \%$ \\ \hline & of the value of $\sigma$, the sample size n should be at least & 33,218 & 1,336 & 336 & 85 & 38 & 22 & 14 \\ \hline \end{tabular} The minimum sample size needed is $\square$ . Is this sample size practical? A. No, because the sample size is excessively large to be practical for most applications. B. No, because the sample size should be as small as possible for most applications. C. Yes, because the sample size should be as large as possible for most applications. D. Yes, because the sample size is small enough to be practical for most applications.