An Average Computer Mouse Inspector Can Inspect 60 Mice Per $\alpha = 0.10$

Multiple Choice

An average computer mouse inspector can inspect 60 mice per hour with a population standard deviation of 8 mice per hour. The 48 computer mice inspectors at a particular factory can only inspect 55 mice per hour. Does the company have reason to believe that these inspectors are slower than average at $\alpha = 0.10$ ?

A) Yes, because the test value -4.33 falls in the noncritical region.
B) No, because the test value -2.47 falls in the noncritical region.
C) No, because the test value -2.47 falls in the critical region.
D) Yes, because the test value -4.33 falls in the critical region.