A design engineer wants to construct a sample mean chart for controlling the service life of a halogen headlamp his company produces. He knows from numerous previous samples that when this service life is in control it is normally distributed with a mean of 500 hours and a standard deviation of 20 hours. On three recent production batches, he tested service life on random samples of four headlamps, with these results

What is the mean of the sampling distribution of sample means when the service life is in control?
A)250 hours
B)470 hours
C)495 hours
D)500 hours
E)515 hours

Question

A design engineer wants to construct a sample mean chart for controlling the service life of a halogen headlamp his company produces. He knows from numerous previous samples that when this service life is in control it is normally distributed with a mean of 500 hours and a standard deviation of 20 hours. On three recent production batches, he tested service life on random samples of four headlamps, with these results

What is the mean of the sampling distribution of sample means when the service life is in control?

What is the mean of the sampling distribution of sample means when the service life is in control?
A)250 hours 
B)470 hours 
C)495 hours 
D)500 hours 
E)515 hours

Quizplus · Accepted Answer

The Answer of A design engineer wants to construct a sample mean chart for controlling the service life of a halogen headlamp his company produces. He knows from numerous previous samples that when this service life is in control it is normally distributed with a mean of 500 hours and a standard deviation of 20 hours. On three recent production batches, he tested service life on random samples of four headlamps, with these results

What is the mean of the sampling distribution of sample means when the service life is in control?
A)250 hours 
B)470 hours 
C)495 hours 
D)500 hours 
E)515 hours

A Design Engineer Wants to Construct a Sample Mean Chart