Weights of women in one age group are normally distributed with a standard deviation sigma of 20 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% confident that the sample mean will not differ from the population mean by more than 3.5 lb.

88.344 or Rounding up to 89

Step-by-step explanation:

When talking about the confidence level, we need to find the z-score for 90% confidence. Since z-scores are constant values we can easily find these online. In this case the z-score for 90% confidence is z = 1.64485

The formula for z-score is as follow

Where

Now we know from the question that

We can easily solve the above equation to find the Standard Deviation

To find Population Size

answer:

c 60% on edg

25

step-by-step explanation: