The St. Joe Company grows pine trees and the average annual increase in tree diameter is 3.1 inches with a standard deviation of 0.5 inch. A random sample of n = 50 trees is collected. What is the probability of the sample mean being less than 2.9 inches?

	a.	0.4977.
	b.	0.0023.
	c.	0.9977.
	d.	0.9954.