Question

# Exercise 10 Moms' Ages If students are helping to conduct this exercise in class, at least 30 students are needed to be able to apply the concepts, namely a 1-sample

z confidence interval for the population mean.Instructions for creating the data set are below.* If you do not have time to collect class data or do not have at least 30 students to perform this activity, then you can use the 'Moms Ages (yrs)'data found in CIForMean_Large Sample_Activity.mtw. * At the beginning of class, ask students to go to the board as they are working on these exercises to record their Moms' ages. Alternatively, students can record their Moms' ages anonymously on a sheet of paper to submit. Once everyone has recorded his or her Mom's age,the instructor can enter the data in Minitab. The instructor can then email the worksheet data to students to ensure that everyone is working with the same data set. In the past year, I've been having students enter their data in Google spreadsheets. Then they don't have to go to the board and record their answers there. Also, Google spreadsheet entries can be entered anonymously. (a) In Minitab, determine the sample mean x for Moms' ages. If you don't remember how to do this, see the Describing Data Numerically lesson. (b) Using your class as a random sample of students who are "similar" to the larger student population (e.g. student ages, similar majors, etc.), determine a two-sided 90% confidence interval for the true mean age u of Moms. Construct this interval by hand or in Minitab. The population standard deviation o = 6 years. (c) Does the above confidence interval actually contain the true mean age u for Moms' ages for students in this category? A. Yes B. No C. We can't be sure (d) Why can we assume that X is approximately normally distributed?

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