Suppose that the company so called Scope Mouthwash wanted to find out reactions of consumers to a new formula that provides for some whitening of the teeth and a degree of tartar control as well. The researcher and Scope marketing manager come to agree on a sample size of 600, so the researcher purchases the names of 600 individuals from a sample supply company. The survey moves along, but the data collection company that is performing the telephone interviews reports to the researcher that the Incidence rate, defined as the percent of individuals in the sample who qualify to take the survey, is 80%, meaning that 20%, or 120 names in the sample, are not usable. So, under this situation, the largest final sample size possible is 480.

At the same time, the data collection company manager reports to the researcher that potential respondents who qualify for survey are refusing to take the survey. The data collection company estimates a refusal rate of 40%, meaning that the Response Rate is 60%. A response rate of 60% means that only 60% of the 480 qualified respondents will be in the final sample. The researcher is now faced with a final sample size of 288, far smaller than the desired size of 600.

You are assigned to adjust sample size to compensate for Incidence Rate and Non-Response.

Note: To accomplish Your task, use the Sample Size Adjustment formula to help marketing researcher to cope with the realities of incidence rate and non-response.