Interpretation The ogives shown are based on U.S. Census data and show the average personal income per capita for each of the 50 states. The data are rounded to the nearest thousand dollars.

(a) How were the percentages shown in graph (ii) computed?

(b) How many states have average per capita income less than 37.5 thousand dollars?

(c) How many states have average per capita income between 42.5 and 52.5 thousand dollars?

(d) What percentage of the states have average per capita income more than 47.5 thousand dollars?