A sample of 80 results in 30 successes. (You may find it useful to reference the z table.) a. Calculate the point estimate for the population proportion of successes, (Round final answer to 3 decimal places.) Point estimate b. Construct the 90% and the 99% confidence intervals for the population proportion (Round final answers to 3 decimal places.) Confidence Level 90% 99% Confidence interval 10 to