A Manufacturing Operation Consists of a Unique System That Produces

A manufacturing operation consists of a unique system that produces an average of 15.5 jet engine propulsion parts every hour. After undergoing a complete overhaul, the system was monitored by observing the number of parts produced in each of 17 randomly selected one-hour periods. The mean is 15.42 with a standard deviation of 0.16. Assume the number of parts produced is approximately normal.
-The null and alternative hypotheses to test whether the number of parts produced by the overhauled system differs from 15.5 is _____.

A) H₀: ? = 15.5 vs.H_a: ? ? 15.5
B) H₀: ? ? 15.5 vs.H_a: ? < 15.5
C) H₀: ? ? 15.42 vs.H_a: ? < 15.42
D) H₀: ? ? 15.5 vs.H_a: ? = 15.5
E) H₀: ? ? 15.5 vs.H_a: ? > 15.5