Question

Suppose a 95% confidence interval for μ turns out to be (1,000, 2,100). To make more useful inferences from the data, it is desired to reduce the width of the confidence interval. Which of the following will result in a reduced interval width? A) Increase the sample size. B) Increase the confidence level. C) Increase the population mean. D) Increase the sample mean.

Answer 1

Answer:

a) Increase the sample size

Step-by-step explanation:

Given that a 95%  confidence interval for μ turns out to be (1,000, 2,100)

The confidence interval is formed as

$\mu+/- Margin of error$

Margin of error = critical value * std dev/sqrt of sample size

Hence for the same confidence level, we cannot change critical value.

The only available ways are either to decrease std deviation or increase the sample size to make it narrower.

If confidence level becomes higher, then confidence interval would be wider.

Here  out of four options the correct option is

a) Increase the sample size