Overview
Question 1. To do this, we need to find the mean, x̄, and then find the maximum margin of error, E. Then, we can use the calculator to find the interval, (x̄ - E, x̄ + E).
- First, find the mean. Under the SLEEP column values, in cell F37, type =AVERAGE(F2:F36).
- Now, calculate the standard deviation in cell F38, by typing =STDEV(F2:F36).
- Now, we can find the maximum margin of error, E, that we need for the confidence interval. To find the maximum margin of error, in cell F39, type = CONFIDENCE.T(0.05,F38,35).
(Note: the 0.05 is based on the 95% level of confidence, the F38 is the standard deviation, and the 35 is the size of our sample).
Now, after following the above-stated instructions, you should have enough to calculate the 95% confidence interval,
(x̄ - E, x̄ + E).
Select the appropriate confidence interval (rounded to two decimal places), Provide the correct interpretation of the confidence interval.
Question 2
Now, we want to calculate the 99% Confidence Interval for SLEEP times. The only difference should be the margin of error.
So, in cell F40, type =CONFIDENCE.T(0.01,F38,35), to find the maximum margin of error for the 99% confidence interval.
Again, you want to use a calculator to find the confidence interval, (x̄ - E, x̄ + E).
Select the appropriate confidence interval (rounded to two decimal places), and provide the correct interpretation of the confidence interval.
Option F95% of students have a sleep time that lies between the bounds of our confidence interval.995% of students have a sleep time that lies between the bounds of our confidence interval.5% of students have a sleep time that lies between the bounds of our confidence interval.