2-37 The Massachusetts Friends of Fish has the following data representing pollutants (in parts million) at 150 sites in the state: Pollutants (in ppm) Frequency Pollutants (in ppm) Frequency N 5.0- 8.9 25.0-28.9 9.0-12.9 29.0-32.9 13.0-16.9 33.0-36.9 17.0-20.9 37.0-40.9 21.0-24.9 Construct an ogive that will help you answer the following questions: (a) Below what value (approximately) do the lowest one-fourth of these observations fall? (b) If the Friends of Fish heavily monitor all sites with more than 30 ppm of pollutants, wha percentage of sites will be heavily monitored