Table 21-1 The following table shows the distribution of income in Marysville. Group Annual Family Income Bottom Quartile (25%) $30,000 and below Third Quartile $30,000 to $59,999 Second Quartile $60,000 to $89,999 Top Quartile $90,000 and above Refer to Table 21-1. Seventy-five percent of all families have incomes below what level? a. $30,000 b. $90,000 c. There is insufficient information to answer this question. d. $60,000