The Quality Control Manager at a Cell Phone Battery Factory

Multiple Choice

The quality control manager at a cell phone battery factory needs to determine whether the mean life of a large shipment of batteries is equal to the specified value of 375 hours. The process standard deviation is known to be 100 hours. A random sample of 64 batteries indicates a sample mean of 350 hours.
-The null and alternative hypotheses to test whether the shipment meets the specified value is _____.

A) H₀: µ ≥ 350 H_a: µ < 350
B) H₀: µ ≠ 375 H_a: µ = 375
C) H₀: µ = 375 H_a: µ ≠ 375
D) H₀: µ ≥ 375 H_a: µ < 375
E) H₀: µ ≤ 375 H_a: µ > 375