Find the necessary sample size.Weights of women in one age g…

Find the necessary sample size.Weights of women in one age group are normally distributed with a standard deviation σ of 12 lb. A researcher wishes to estimate the mean weight of all women in this age group. Find how large a sample must be drawn in order to be 90 percent confident that the sample mean will not differ from the population mean by more than 2.4 lb.