A new variety of turf grass has been developed for use on golf courses, with the goal of obtaining a germination rate of 80%. To evaluate the grass, 20 seeds are planted in a greenhouse so that each seed will be exposed to identical conditions. If the 80% germination rate is correct, calculate the probabilities below.

 a. What probability distribution model would be appropriate for describing the number of grass seeds that will germinate. Explain. 

b. What is the probability that exactly 17 seeds will germinate? 

c. Calculate the probability that less than 15 seeds will grow. 

d. What is the probability that more than 14 seeds will grow?