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Chapter 2: Problem 30

Deal with an experiment to study the effects of financial incentives to quit smoking. 19 Smokers at a company were invited to participate in a smoking cessation program and randomly assigned to one of two groups. Those in the Reward group would get a cash award if they stopped smoking for six months. Those in the Deposit group were asked to deposit some money which they would get back along with a substantial bonus if they stopped smoking. After six months, 156 of the 914 smokers who accepted the invitation to be in the reward-only program stopped smoking, while 78 of the 146 smokers who paid a deposit quit. Set up a two-way table and compare the success rates between participants who entered the two programs.

Short Answer

Expert verified
To calculate the success rates, divide the number of people who quit smoking by the total number of people in each program. The Reward program had a success rate of about 17.07%, and the Deposit program had a success rate of about 53.42%. Therefore, it appears that the Deposit program was more effective.

Step by step solution

01

Set up a two-way table

First, organize the given data into a two-way table. The two columns would represent the two groups: Reward and Deposit. The rows would indicate the number of people who quit smoking and those who didn't quit for each group. Based on the given, the table would look like this:| | Reward | Deposit ||---------|------------|-----------|| Quit | 156 | 78 || Didn't | 914-156 | 146-78 |
02

Calculate the success rates

Next, calculate the success rates for both groups. This is done by dividing the number of people who quit smoking by the total number of people who were in the program for each group. The formulas to calculate the success rates would be as follows:Success rate for Reward group = Number who quit (156) / Total (914)Success rate for Deposit group = Number who quit (78) / Total (146)
03

Compare the success rates

Compare the success rates calculated in step 2 by observing which group has a higher success rate, and discuss the comparison in terms of the effectiveness of each program.

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