Question

Are children heavier now than they were in the past? The National Health Examination and Nutrition Survey published in 2004 reported that the mean weight of six-year-old girls in the United States was 49.3 pounds. Another survey, published in 2012, reported that a sample of 177 six-year-old girls had an average weight of 51.9 pounds. Assume the population standard deviation is σ = 17 pounds. Can you conclude that the mean weight of six-year-old girls is higher in 2012 than in 2004? (Show all the usual steps!)

A. Yes
B. No

Answer 1

The hypothesis test indicates that, given a mean weight of 49.3 pounds in 2004 and an average weight of 51.9 pounds in a 2012 sample with a population standard deviation of 17 pounds, the mean weight of six-year-old girls is statistically higher in 2012 than it was in 2004.

Step-by-step explanation:

To determine if the mean weight of six-year-old girls is higher in 2012 than it was in 2004 based on the data from the National Health Examination and Nutrition Survey, we will perform a hypothesis test. We are given that the mean weight in 2004 was 49.3 pounds and in a 2012 sample the average weight is 51.9 pounds, with the population standard deviation (σ) being 17 pounds.