The common fruit fly Drosophila melanogaster is the most studied organism in genetic research because it is small, easy to grow, and reproduces rapidly. The length of the thorax (where the wings and legs attach) in a population of male fruit flies is approximately Normal with a mean 0.800 (mm) and standard deviation 0.078 mm.
(a) What proportion of flies have thorax length 0.9 mm or longer?
(b) What proportion have thorax length between 0.9 mm and 1 mm?