Mayo Clinic in Minnesota Essay Example for Free

Mayo Clinic in Minnesota Essay Problem 1 (a) One of the most promising approaches to helping people to quit smoking is the nicotine patch. The patch gradually dispenses nicotine into the blood. In a 1994 experiment at the Mayo Clinic in Minnesota, 240 volunteer smokers participated in a study of the effectiveness of the nicotine patch. All of the volunteers were between the ages of 20 and 30, were in good health, smoked at least 20 cigarettes a day and wanted to quit. They were randomly assigned to receive either 22-mg nicotine patches or placebo patches. All 240 participants also received counseling about quitting smoking. After one year, 33 of the 120 participants with the nicotine patch had quit smoking while 17 of those with the placebo patch had quit. (a) What are the explanatory and response variables in this case? The response variable is whether they quit smoking or not. The explanatory variables are the use (or otherwise) of a nicotine patch, and the counseling they received. 2. (Points: 10) Problem 1 (b) One of the most promising approaches to helping people to quit smoking is the nicotine patch. The patch gradually dispenses nicotine into the blood. In a 1994 experiment at the Mayo Clinic in Minnesota, 240 volunteer smokers participated in a study of the effectiveness of the nicotine patch. All of the volunteers were between the ages of 20 and 30, were in good health, smoked at least 20 cigarettes a day and wanted to quit. They were randomly assigned to receive either 22-mg nicotine patches or placebo patches. All 240 participants also received counseling about quitting smoking. After one year, 33 of the 120 participants with the nicotine patch had quit smoking while 17 of those with the placebo patch had quit. (b) Compute the p-value for a one-sided Z-test of whether the nicotine patch significantly increases the likelihood of quitting smoking. Be sure to state your hypotheses, defining p1 and p2. 33 / 120 = 0. 275 = p1 (Proportion who quit using patch) 17 / 120 = 0. 142 = p2 (Proportion who quit without using patch) Null Hypothesis Ho: Using a nicotine patch and counseling does not increase the probability of quitting smoking, compared to using counseling alone, for 20-30 year-olds who smoke more than 20 cigarettes per day. Ho: p1 – p2 = 0 Alternative Hypothesis Ha: Using a nicotine patch with counseling is more likely to result in quitting smoking than using counseling alone, for 20-30 year-olds ho smoke more than 20 cigarettes per day. Ha: p1-p20 Check if normal dist applies: samples are independent (no reason to think sample is biased) sample size 10% (only 240 from large population) np1=120*0. 275=33, n(1-p1)=87; np2=17, n(1-p2)=103 Z = (p2-p1)/sqrt(p1(1-p1)/n1+p2(1-p2)/n2) = (0. 275-0. 142)/(0. 0517) = 2. 578 So p = 0. 005