The population of current statistics students has ages with mean muμ and standard deviation sigmaσ. samples of statistics students are randomly selected so that there are exactly 4545 students in each sample. for each sample, the mean age is computed. what does the central limit theorem tell us about the distribution of those mean ages?

Because n > 30, the sampling distribution of the mean ages can be approximated by a normal distribution with mean µ and standard deviation σ ÷ √(45) .The central limit theory applies whenever n > 30. Because n > 30, the sampling distribution of the mean ages can be approximated by a normal distribution with mean µ and standard deviation σ ÷ √(n) .

Idon’t understand this but 90