InferenceScenarios_2013

# Advice blood choleste rol advice blood cholesterol

This preview shows pages 12–14. Sign up to view the full content.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Conclusion: There is some evidence that Type A provides greater reduction in blood cholesterol than Type B, but the sample size is too small to make a definitive conclusion. Further testing is warranted, however. 13
c) An optional analysis would be to check whether the random assignment to the two groups did in fact give two comparable groups. If the two groups really are comparable then the Before cholesterol levels in both groups should be similar. A two-sample t-test to compare the means of the two groups using the “Before” data gives a t-stat = 1.45, with a P-value = 0.17, indicating that there is no evidence of a difference in starting cholesterol. Here is how the spreadsheet looks in Excel, and what the output would look like. Subjec t Atyp e Type Before After Diff Type Before After Diff 1 A 1 421 346 75 1 421 346 75 2 B 2 297 290 7 1 542 530 12 3 B 2 278 259 19 1 333 287 46 4 B 2 220 196 24 1 344 306 38 5 A 1 542 530 12 1 426 374 52 6 A 1 333 287 46 1 331 280 51 7 B 2 267 241 26 1 444 387 57 8 A 1 344 306 38 1 261 217 44 9 A 1 426 374 52 1 224 207 17 10 A 1 331 280 51 1 244 228 16 11 B 2 307 283 24 2 297 290 7 12 A 1 444 387 57 2 278 259 19 13 B 2 317 303 14 2 220 196 24 14 A 1 261 217 44 2 267 241 26 15 A 1 224 207 17 2 307 283 24 16 B 2 467 415 52 2 317 303 14 17 B 2 213 186 27 2 467 415 52 18 A 1 244 228 16 2 213 186 27 19 B 2 312 273 39 2 312 273 39 t-Test: Paired Two Sample for Means t-Test: Two-Sample Assuming Equal Variances Before After Type 1 Type 2 Mean 328.8 295.2 Mean 40.8 25.8 Variance 8464.0 7348.3 Variance 413.1 175.9 Observations 19 19 Observations 10 9 Pearson Corr, 0.981 Pooled Variance 301.5 Hypo. Mean Diff. 0 Hypo. Mean Diff 0 df 18 df 17 t Stat 7.91 t Stat 1.88 P(T<=t) one-tail 0.00 P(T<=t) one-tail 0.04 t Critical one-tail 1.73
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern