Question

n 1990, the mean height of women 20 years of age or older was 63.7 inches based on data obtained from theCDC. Suppose that a random sample of 45 women who are 20 years of age or older in 2015 results in a meanheight of 63.9 inches with a standard deviation of 0.5 inch. Does your sample provide sufficient evidencethat women today are taller than in 1990

Answer 1

The sample does not provide sufficient evidence that women today are taller than women in 1990.

The difference in mean height is not significant to arrive at such a conclusion.

Explanation:

Mean height of women 20 year of age or older in 1990 = 63.7 inches

Mean height of women 20 years of age or older in 2015 = 63.9 inches

The standard deviation of the mean height in 2015 = 0.5 inch

The difference between the two years' mean height is 0.2 (63.9 - 63.7) inch.

This difference is less than the standard deviation of the mean height in 2015.

Therefore, the difference does not provide sufficient evidence that women today are taller than women in 1990.