19. Population size is the most important determinant of effective sample size. A) True B) False 20. Pie charts are useful for depicting changes over time. A) True B) False 21. The median is always equal to the mean. A) True B) False 22. Data mining is a long-established field of market research. A) True B) False 23. Persuasion should never be used in the personal presentation of a marketing research report. A) True B) False _24. Clients tend to prefer long text-based reports to shorter ones. A) True B) False 25. Common arithmetic scales are used with ordinal scales. A) True B) False