A Bloomberg BusinessWeek North American subscriber study collected data from a sample of 2,861 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. Required:
a. What is the population of interest in this study?
b. Is annual income a qualitative or quantitative variable?
c. Is ownership of an American Express card a qualitative or quantitative variable?
d. Does this study involve cross-sectional or time series data?
e. Determine whether the following two statistical inferences may be made based on the sample data collected.