Production Process

Question

For a sample size of 1, the sampling distribution of the mean will be normally distributed
A. regardless of the shape of the population

B. only if the shape of the population is positively skewed

C. only if the population values are larger than 30

D. only if the population is normally distributed
 

Question

A 95% confidence interval for the population mean indicates that
 

A. with an infinite number of samples, there’s a 5% chance that the population mean will be outside the interval

B. more sampling is required to increase the confidence interval to 100%

C. the sampling process is biased

D. 95% of the observations from any sample will fall within the interval
 

Question

A random sample of 16 ATM transactions at the First National Bank of Flintrock revealed a mean transaction time of 2.8 minutes with a standard deviation of 1.2 minutes. The width, in minutes, of the 95% confidence interval for the true mean transaction time is
 

A. ± 0.639

B. ± 0.588

C. ± 0.300

D. ± 2.131
 

Question

All other things being equal, which is narrower, a 95% confidence interval with n=100 or a 99% confidence interval with n=30?
 

A. The 95% confidence interval

B. The 99% confidence interval

C. The same width

D. Need the margin of error to tell
 

Question

When the only sources of variation in a production process are caused by chance, the process is said to be

 A. out of balance but under control

B. out of control but in balance

C. under control

D. out of control