Discuss the following:
Q: The Gibbs Baby Food Company wishes to compare the weight gain of infants using their brand versus their competitor's. A sample of 40 babies using the Gibbs products revealed a mean weight gain of 7.6 pounds in the first three months after birth. The standard deviation of the sample was 2.3 pounds. A sample of 55 babies using the competitor's brand revealed a mean increase in weight of 8.1 pounds, with a standard deviation of 2.9 pounds. At the .05 significance level, can we conclude that babies using the Gibbs brand gained less weight? Compute the p-value and interpret it. Set this up using the 5-step hypothesis testing procedure outlined in your textbook:
1. State the null & alternative hypotheses - remember that the alternative hypothesis is our research question
2. Design the study and select a level of significance (alpha)
3. Identify the test statistic - which of the formulas will work best with our data?
4. Formulate a decision rule - under what conditions can we reject the null hypothesis and accept the alternate?
5. Take a sample and arrive at a decision to reject or not reject the null - write a short summary statement communicating your decision