A 99% confidence interval estimate can be interpreted to mean that A. if all possible samples are taken and confidence interval
estimates are developed, 99% of them would include the true population mean somewhere within their interval. B. we have 99% confidence that we have selected a sample whose interval does include the population mean. C. Both of the above. D. None of the above..
Confidence interval is a type of range which includes the true value of the population parameter. Confidence interval can be determined from the statistics of the researched data.
For example:
z_c = 1.96 at 95% confidence ⇒ Z- critical value
n = 50
x - bar = 375
SD = 20
Margin of error, E = ?
E = 5.5437
Therefore,
95% CI:
= (375 - 5.5437, 375 + 5.5437)
= (369.4563 , 380.5437)
Hence, 95% confidence interval is (369.4563, 380.5437). This includes the value of x-bar = 375 in the confidence interval.
