cheatgrass is an annual grass plant native to eurasia that was unintentionally introduced into the great basin area of utah and wyoming. during the colonization phase of cheatgrass invasions, populations exhibit rapid growth. biologists have estimated a finite rate of increase of 1.6. there are 150 cheatgrass plants in a single plot of land six years after the initial colonization. approximately how many plants were in the initial invasion at time zero