A BusinessWeek North American subscriber study collected data from a sample of 2861 subscribers. Fifty-nine percent of the respondents indicated an annual income of $75,000 or more, and 50% reported having an American Express credit card.
a. What is the population of interest in this study?
b. Is annual income a categorical or quantitative variable?
c. Is ownership of an American Express card a categorical or quantitative variable?
d. Does this study involve cross-sectional or time series data?
e. Describe any statistical inferences BusinessWeek might make on the basis of the survey.