The Average Diameter of Sand Dollars on a Certain Island

Multiple Choice

The average diameter of sand dollars on a certain island is 3.00 centimeters with a standard deviation of 1.00 centimeters. If 9 sand dollars are chosen at random for a
Collection, find the probability that the average diameter of those sand dollars is more
Than 2.60 centimeters. Assume that the variable is normally distributed.

A) 0.885
B) 0.385
C) 0.615
D) 0.820