Does anyone know how to solve these two problems.

Question

Solve the problem. Find the critical value za/2 that corresponds to a degree of condfidence of 98%.

Express the confidence interval in the form of ^p _+E.

0.033<p>0.493

Answer 1

Confidence interval using proportions:

CI98 = p + or - (2.33)(sqrt of pq/n)
...where + or - 2.33 represents 98% confidence using a z-table.
(q = 1 - p ...and... n = sample size)

I hope this helps.