The question asks for the null hypothesis ($H_0$) and alternative hypothesis ($H_1$) for testing whether the mean weight of newborn girls differs from the reported mean weight of 7.5 pounds for newborn boys.

Hypotheses:

1. Null Hypothesis ($H_0$): There is no difference in the mean weight of newborn girls compared to 7.5 pounds.

   • $H_0: \mu = 7.5$

2. Alternative Hypothesis ($H_1$): There is a difference in the mean weight of newborn girls compared to 7.5 pounds.

   • $H_1: \mu \neq 7.5$

This is a two-tailed test because we are checking for any difference (not specifically greater or less).

Let me know if you'd like a detailed explanation of how hypotheses are structured or if you have further questions.

Expanding Your Understanding:

1. What is the difference between one-tailed and two-tailed tests?
2. How is the significance level ($\alpha$) related to the hypothesis test?
3. What steps follow after stating the hypotheses in hypothesis testing?
4. What statistical test would be appropriate for comparing the mean of one sample to a known value?
5. How would the sample size impact the hypothesis testing process?

Tip: Always clearly define the hypotheses first; they form the foundation for your entire analysis.