A company checking the productivity of its assembly line monitored a random sample of workers for several days. They found that a 95% confidence interval for the mean number of items produced daily by each worker was (23,27). Which is true?
A) 95% of all the workers average between 23 and 27 items a day.
B) 95% of the workers sampled produced between 23 and 37 items a day.
C) We're 95% sure that the mean daily worker output is between 23 and 27 items.
D) Workers produce an average of 23 to 27 items on 95% of the days.
E) 95% of samples would show mean production between 23 and 27 items a day.

Question

Quizplus · Accepted Answer

The confidence interval represents our level of confidence (95%) that the true population mean falls between the given range (23 and 27). Option A is incorrect because we cannot make any inferences about all workers, only the ones sampled. Option B is incorrect because it's not possible for a worker to produce more than 27 items when the upper limit is 27. Option D is incorrect because we do not have any information about individual worker variation from day to day. Option E is incorrect because the statement refers to multiple samples, but we only have one sample here.

A Company Checking the Productivity of Its Assembly Line Monitored