Please help! I have no idea how to solve this! To test the efficacy of a new cho
ID: 3126641 • Letter: P
Question
Please help! I have no idea how to solve this!
To test the efficacy of a new cholesterol-lowering medication, 10 people are selected at random. Each has their LDL levels measured (shown below as Before), then take the medicine for 10 weeks, and then has their LDL levels measured again (After). Give a 96.6% confidence interval for mu_B - mu_A, the difference between LDL levels before and after taking the medication. Confidence Interval = at 96.6% confidence. Give your answer as an open interval, in the form (a, b) where A is the lower bound and B is the upper bound.Explanation / Answer
The differences are
22
-4
-8
8
16
-6
32
20
12
34
Calculating the standard deviation of the differences
s = 15.11584893
Thus, the standard error of the difference is sD = s/sqrt(n):
sD = 4.780051139
Calculating the mean of the differences
XD = 12.6
For the 0.966 confidence level,
alpha/2 = (1 - confidence level)/2 = 0.017
t(alpha/2) = 2.497518163
lower bound = XD - t(alpha/2) * sD = 0.661735459
upper bound = XD + t(alpha/2) * sD = 24.53826454
Thus, the confidence interval is
( 0.661735459 , 24.53826454 ) [ANSWER]