Question

Does the confidence interval in a previous problem became longer or shorter if we take y = 0.99 instead of 0.95? How many times?

Answer 1

The confidence interval is given by

Point Estimate $\pm$ Margin of error (E)

The margin of error is given by

E = critical value * Standard error ( S.E. )

Here critical value depends on confidence level. As confidence level increases critical value increases and hence margin of error increases .

If margin of error greater confidence interval becomes longer.

So for confidence level 0.99 confidence interval is longer than the confidence level 0.95.