The Jubilee variety of sweet corn typically grows on average about 7 ft before being harvested. Specifically, if we measure the height of each corn plant on a large field, we get a normal distribution with =7 and =0.6 approximately.

a) What is the probability that a corn plant is between 6 and 7 ft tall?

b) What is the probability that a corn plant is more than 8 ft tall?

c) A farmer noticed that 47% of his corn plants were smaller than 6 ft tall. Should he be worried?