Question

Which of the following would increase the width of a confidence interval for a population​ mean? Choose the correct answer below. A. Increase the level of confidence B. Decrease the sample standard deviation. C. Increase the sample size D. All of the above

Answer 1

Answer:

A. Increase the level of confidence

Step-by-step explanation:

The margin of error is given by:

The margin of error is:

$M = \frac{Ts}{\sqrt{n}}$

In which T is related to the level of confidence(the higher the level of confidence, the higher T is), s is the standard deviation of the sample and n is the size of the sample.

Increase the width:

That is, increasing the margin of error, as the width is twice the margin of error, the possible options are:

Increase T -> increase confidence level.

Increase s -> Increase the standard deviation of the sample.

Decrease n -> Decrease the sample size.

Thus, the correct answer is given by option A.