An IQ test is designed so that the mean is 100 and the standard deviation is 12 for the population of normal adults. Find the sample size necessary to estimate the mean IQ score of statistics students such that it can be said with 95​% confidence that the sample mean is within 2 IQ points of the true mean. Assume that σ=12 and determine the required sample size using technology. Then determine if this is a reasonable sample size for a real world calculation.

The required sample size is

Here are summary statistics for randomly selected weights of newborn​ girls: n=220​, x=29.9 ​hg, s=6.7 hg. Construct a confidence interval estimate of the mean. Use a 98​% confidence level. Are these results very different from the confidence interval 28.3 hg<μ<30.9 hg with only 19 sample​ values, x=29.6 ​hg, and s=2.2 ​hg

What is the confidence interval for the population mean μ​?

hg<μ<hg ​(Round to one decimal place as​ needed.)