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 $95\%$ confident that the sample standard deviation s is within $40\%$ of $.$ Is this sample size practical?

$\backslash$table$[[\backslash$table$[[$To be $95\%$ confident that s is$],[$within$]],1\%,5\%,10\%,20\%,30\%,40\%,50\%$