Map out the experimental design in terms of R's, X's, and O's. Specify the null hypothesis that should be examined in each design, and then state the statistical test that should be used to analyze the data,
1. The Tobacco institute wanted to test the effectiveness of two booklets that discuss the issue of whether advertising causes children to start smoking. A random sample of 1200 was selected from a mailing list of 10,000 people. The sample was randomly divided into three groups of size 400 each; one group received one version of the booklet, the second received the other version, and the third group received neither booklet. One week later the attitudes of all three groups about whether advertising causes children to smoke were measured on an interval scale.
2. A large national chain of department stores wanted to test the effectiveness of a promotional display for a new brand of household appliances. Fifty stores were randomly selected from a total of 263 stores. The sample of 50 stores was randomly divided into two groups of 25 stores each. Only one group used the promotional display. For three weeks, sales of the new brand of appliances were monitored for both groups.
3. (Note: This problem describes two experiments) First Experiment: A medium-sized life insurance company was concerned about its poor public image. The public relations department designed a 20-page bulletin that was to be mailed to all existing and prospective clients and shareholders in order to allay any negative feelings that might have resulted from the bad publicity. Prior to incurring the expenses of the complete mailing, the department randomly selected 300 clients and shareholders and mailing the 20- page bulletin to them. Attitudes toward the company were measured on an interval scale before and after sending the bulletin.
Second Experiment: Management was dissatisfied with the first experiment and requested that another random sample of 500 clients and shareholders be generated. This sample was to be randomly divided into two groups of 250 respondents each. The bulletin was to be mailed to one group of respondents. Attitudes toward the company were to be measured for both groups on an interval scale two weeks after mailing the bulletin.