A market research consultant hired by a leading soft drink company is interested in determining whether there is a difference between the proportions of female and male consumers who favor the company’s low calorie brand over the leading competitor’s low-calorie brand in a particular urban location. A random sample of 250 consumers from the market under investigation is provided in the file P08_18.xlsx.
a. After separating the 250 randomly selected consumers by gender perform the statistical test and report a p-value. At which levels of will the market research consultant conclude that there is essentially no difference between the proportions of female and male consumers who prefer this company’s brand to the competitor’s brand in this urban area?
b. Marketing managers at this company have asked their market research consultant to explore further the potential differences in the proportions of women and men who prefer drinking the company’s brand to the competitor’s brand. Specifically, the company’s managers wants to know whether the potential difference between the proportions of female and male consumers who favor the company’s brand varies by the age of the consumers.
Using the same random sample of consumers as in part a, assess whether this difference varies across the four given age categories: under 20, between 20 and 40, between 40 and 60, and over 60. Specifically, run the test in part a four times, one for each age group. Are the results the same for each age group?