2. The principal randomly selected six students to take an aptitude test. Their scores (from a normal distribution) were:
83.0 84.1 83.5 83.7 84.1 73.5
a. Determine a 90 percent confidence interval for the mean score for all students. Show all work. Identify the standard error, and all calculations of the margin of error. Does it appear as if the mean score was better than 84? Write the findings as you would in a report (interpret the interval.)
b.Assume now that sigma was known to be 4.17. What is the confidence interval for the mean score? Show your work. How is it different above? Why?
Get Answers For Free
Most questions answered within 1 hours.