Question

6. Which one of the followings will decrease width of a confidence interval?

(underline and bold the correct answer letter)
A. By increasing confidence level.
B. By increasing variability.
C. By increasing sample size.
D. By decreasing sample size.

Answer 1

The width of a confidence interval decreases when the sample size is increased, because this leads to a decreased error bound and a narrower interval.

Step-by-step explanation:

The question pertains to statistics and the factors that influence the width of a confidence interval. The correct answer to which factor will decrease the width of a confidence interval is:

C. By increasing sample size.

When you increase the sample size, the error bound decreases, which in turn narrows the confidence interval. Conversely, factors such as increasing the confidence level or variability or decreasing the sample size would lead to a wider confidence interval.