A 95 confidence interval for the mean m of a population is c

A 95% confidence interval for the mean m of a population is computed from a random sample and found to be 9+-3. We may conclude: Select one:

a. if we took many, many additional random samples and from each computed a 95% confidence interval for M, approximately 95% of these intervals would contain M.

b. All the other answers.

c. there is a 95% probability that M is between 6 and 12.

d. there is a 95% probability that the true mean is 9 and there is a 95% chance that the true margin of error is 3.

Solution

95% confidence interval means:

If we used the same sampling method to select different samples and computed confidence interval for each sample, the true population parameter to fall within the interval estimates 95% of the time.

So option (a) is correct.