Question

A sleep disorder specialist wants to test the effectiveness of a new drug that is reported to increase the number of hours of sleep patients get during the night. To do so, the specialist randomly selects nine patients and records the number of hours of sleep each gets with and without the new drug. The results of the two-night study are listed below. Using this data, find the 90% confidence interval for the true difference in hours of sleep between the patients using and not using the new drug. Assume that the hours of sleep are normally distributed for the population of patients both before and after taking the new drug.

Patient	1	2	3	4	5	6	7	8	9
Hours of sleep without the drug	5.4	5.4	2.2	3.7	3.4	5.5	2.6	4.2	4.2
Hours of sleep with the new drug	8.1	6.5	3.2	5.3	4.5	8	5.1	5.3	6.4

Step 1 of 4 :  

Find the point estimate for the population mean of the paired differences. Let x1 be the number of sit-ups before taking the course and x2 be the number of sit-ups after taking the course and use the formula d=x2−x1 to calculate the paired differences. Round your answer to one decimal place.

Step 2 of 4:

Calculate the sample standard deviation of the paired differences. Round your answer to six decimal places.

Step 3 of 4:

Use the 90% confidence interval for the true difference between the population means. Assume that both populations are normally distributed.

Step 4 of 4:

Construct the 90% confidence interval. Round our answers to one decimal places.

Answer 1