A simple random sample of 1800 hospital patients admitted in a given year shows that 82.5% had an error on their medical bill. Which interval is the 95% confidence interval for the percent of all the hospital's admitted patients admitted that year who had an error on their medical bill?

We are given a sample size of 1800 hospital patients. The data for a year shows that 82.5% of the patients had an error on their medical bill, meaning:

1800 * 0.825 = 1485 patients have errors on their medical bills.

Given the confidence interval of 95% with an equivalent z value of 1.96, the number of patients who have medical errors on their medical bills is:

1485 patients + - (considering the confidence interval, z value 1.96) use the z-test to arrive at the final answer.