Question

2. (50pts) Now, you must determine if a new cholesterol drug is effective. You know that the drug lowers blood pressure (hint: pick correct alternate hypothesis) but are not sure if the difference is significant. With 95% confidence, is there a statistically significant difference in blood pressure (mmHg) before and after administration of the drug?

Patient #	BP before drug (mm Hg)	BP after drug (mm HG)
1	154	123
2	162	143
3	178	132
4	184	165
5	160	143
6	192	165

Answer 1

Before	after	dbar
154	123	31
162	143	19
178	132	46
184	165	19
160	143	17
192	165	27

x1bar - x2bar = 26.50

s(dbar) = 10.9864

SE = s(dbar)/sqrt(n) = 4.4852

CI = 95%

DF = 5

t-value = 2.5706

ME = t*SE = 2.5706*4.4852 = 11.5295

Confidence Interval (x1bar - x2bar) +/- ME

Lower bound = 14.97053

Upper bound = 38.02947

Confidence Interval (14.9705 , 38.0295 )

As 0 does not lie in the above calculated, we reject the null hypothesis

there is a statistically significant difference in blood pressure (mmHg) before and after administration of the drug