Question

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..

Answer 1

Answer:

Option (C) is correct.

Explanation:

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.