water from industrial plants must be treated before entering the sewer system. water that is too acidic or too basic will harm the pipes. A semiconductor manufacturer must adjust the pH of any waste water from the process to between 4.0 and 10.0

The scatter plot shows the number of animal cells clara examined in a laboratory in different months: plot ordered pairs 1, 20 and 2, 60 and 3,100 and 4, 140 and 5, 180 what is the approximate predicted number of animal cells clara examined in the 9th month?