3. According to the National Center for Health Statistics, the mean weight for an adult female in the United States is 164.7 pounds. A group promoting healthier eating habits feels strongly that it...

3. According to the National Center for Health Statistics, the mean weight for an adult female in
the United States is 164.7 pounds. A group promoting healthier eating habits feels strongly that
it has made an impact in one community by reducing the mean weight of women in that
community. A simple random sample of 39 women in this community yielded a mean weight of
162.9 pounds. Assuming that the population standard deviation is 5.6 pounds, is the sufficient
evidence at a a = 0.05 significance level to say that the mean weight of women in this
community is lower than 164.7 pounds?