If he uses upper and lower control limits of 520 and 480 hours, what is his risk (alpha) of concluding service life is out of control when it is actually under control (Type I error)?
A)0.0026
B)0.0456
C)0.3174
D)0.6826
E)0.9544

Question

Quizplus · Accepted Answer

The risk of a Type I error, or alpha, is the probability of concluding that the process is out of control when it is actually in control. This is typically represented by the area in the tails of the normal distribution beyond the control limits. Given the options, 0.0456 is the most reasonable value for alpha, representing a typical significance level of 4.56%.

If He Uses Upper and Lower Control Limits of 520