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# Gibbs Baby Food Company: State the null & alternative hypotheses and design the study and select a level of significance

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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

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) -
here, it's given to us

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