Question

What can we do to make the confidence interval narrower in Q.4.2, without changing the confidence level?

Answer 1

Here we need to make the confidence interval narrower , but without changing the confidence level .

So these can be acheived by

Increasing the sample size. Often, the most practical way to decrease the margin of error is to increase the sample size as sample size is inversly proportional to margin of error .

Decrease the variability. The less variablity we have , the more precisely you can estimate a population parameter and as variability is directly proportional to margin of error so reducing it will reduce our confidence interval.

So , if need to keep confidence level same then we can make the confidence interval narrower (smaller) by incresing sample size.

{ Note that- actuall Q.4.2 is not mentioned above , no idea about that question , but in genrally if we need to make confidence interval narrower (smaller) without changing confidence level , we can increase sample size n or either reduce sample variability , since reducing variability in not something practical , so we need to increase sample size . If there are any other doubts , you can ask in comment box. }