Question:
Answer the following questions showing all work. If you use Minitab Express include the appropriate output (copy + paste) along with an explanation. Output without explanation will not receive full credit. Round all answers to 3 decimal places. If you have any questions, post them to the course discussion board.
1. For each of the following, compute the correct degrees of freedom and find the correct t multiplier for constructing a confidence interval for a population mean using Minitab Express.
A. Confidence level 85%, , df = _____, t* = ______
B. Confidence level 85%, , df = _____, t* = ______
C. Confidence level 95%, , df = _____, t* = ______
D. Confidence level 95%, , df = _____, t* = ______
E. How does the t multiplier change as the confidence level changes?
F. How does the t multiplier change as the sample size changes?
2. For the following scenarios, if you were to construct a confidence interval, what would be the appropriate multiplier? (State whether z* or t* AND look up the number) [20 points]
A. You want to estimate the proportion of Penn State students who own a Mac with 95% confidence. You take a simple random sample of 30 Penn State students.
B. You want to estimate the average weight of female Maine Coon cats with 95% confidence. You have a sample of 16 female Maine Coons.
C. You want to construct a 99% confidence interval for the mean number of credits completed by students enrolled in STAT 200 this semester across all campuses. You take a random sample of 850 students.
D. You want to construct a 90% confidence interval for the proportion of registered Pennsylvanian voters who plan to vote for Candidate A. You take a random sample of 50 registered voters in Pennsylvania.
E. You want to construct a 90% confidence interval for the average height of all Penn State World Campus students. You have a random sample of 27 World Campus students.