Two baby-food manufacturers are competing, and manufacturer of brand A believes that their brand causes more weight gain in infants than manufacturer of brand B. A sample of size 15 fed their babies brand A for two months, and saw an average weight gain of 36.93 ounces, with a standard deviation of 4.23 ounces. A sample of size 25 fed their babies brand B and saw an average weight gain of 31.36 ounces with a standard deviation of 3.35 ounces. A sample of size 25 fed their babies brand B and saw an average weight gain of 31.36 ounces with a standard deviation of 3.35 ounces. Required:
a. Create a 95% confidence interval for the difference in weight gain between the two baby food brands.
b. Interpret your interval from (a) in terms of the problem.
c. Does your interval suggest one brand of baby food causes more weight gain than the other? Explain.