The project is about comparing the population mean weight of baby boys with the population mean weight of baby girls. So, we want to know if there is a difference between the weight of boys and the weight of girls on average.

Perform the two-tailed hypothesis test, and constructing a confidence interval for the difference of the population means. the hypothesis test:

1. Stated what do you want to test (what is the problem about)
2. Define the population parameters that you will be testing
3. State the null and alternate hypothesis using mathematical symbols
4. State the significance level
5. State the conditions for normal distribution and whether or not they are fulfilled.
6. Write down the formula that you will be using to calculate the test statistic. Plugin the appropriate numbers (you can use the calculator functions under the STAT menu, to find the actual numerical value and degrees of freedom if needed).
7. Based on your alternate hypothesis, draw the z or t distribution as appropriated and shade in the appropriate area(s)
8. Write the appropriate formula that will be used to calculate the p-value (here you will need to use the normalcdf, tcdf, invNorm or invT as appropriate.)
9. Write in words the statistical meaning of the p-value
10. Write in words the conclusion to the problem posted in Project-Assignment 1 question 4.

the confidence interval:

1. State the confidence level that you will use for the confidence interval (any confidence level 90% or above is acceptable).
2. Write down the formula that you need to use (from the chapter 10 table) to calculate the confidence interval, and plug in the appropriate numbers.
3. Show the appropriate work for finding the critical value (you need to show which of the following functions -normalcdf, tcdf, invNorm or invT - you are using and write down how you use it). Draw the z or the t distribution and shade the appropriate area.
4. Calculate the confidence interval. You may use the calculator functions under the STAT menu to find the lower and the upper limit of the interval.
5. Interpret the confidence interval
6. Explain what the confidence interval means in the context of your problem. Based on your confidence interval can you decide which mean is bigger. Explain.