Question

If the confidence level is increased from 90% to 99% for an srs of size n, the width of the confidence interval for the mean ? will: decrease. stay the same. increase. the answer cannot be determined with the information given

Answer 1

Answer: increase

Explanation:

• In statistics , a confidence level gives the proportion of all possible samples that are expected to contain the true population parameter (average , percentage etc).

When we increase the confidence level , we actually increase the error bound.

So , it increases the margin of error.

Therefore , if the confidence level is increased from 90% to 99% for an srs of size n then the width of the confidence interval for the mean increases.

Hence , the correct answer is "increase" .

Answer 2

In most cases, if the confidence level is increased from 90% to 99%, the width of the confidence interval for the mean will also increase or will become wider. As we increase confidence level we are increasing the error, thus making the confidence interval wider. The opposite happens when confidence level is decreased — it decreases errors so confidence interval are narrower.