A state's legislature was considering the funding of its parks system. As part of the considerations, a study was done to look at the number of unique visitors to a selection of the state's parks over the Memorial Day weekend. The histogram below summarizes the data. Use the histogram to answer each of the questions. Frequency (Number of parks) 10- 9 8. 7. 6- 5 4+ 3 2 1 0 120 to 269 270 to 419 420 to 569 570 to 719 Number of unique visitors (a) What is the class width? (b) One class is the least frequent. How many parks are in this class? 0 (c) According to the histogram, what is the total number of parks?