Answer
The approximate increase is nearly 300 percent or three times. Therefore, the number of predators of borers is three times the number of predators when the forest cover is increased from 15 to 30 percent.
Work Step by Step
The population of predators of borers is given per hectare area. Forest cover is given in percentage. The number of borer predators when forest cover is 15 percent is approximately 4 per hectare from the given graph. Similarly, the number of borer predators when the forest cover is 30 percent is 11 per hectare.
the percentage increase in predator is = 11/4*100=2.75 or 275 percent.
