A local animal clinic noted that in a sample of 400 sick animals, 80 were referred to them by the local animal hospital. 1. Check the conditions of the interval estimate. 2. Calculate the point estimate of the population proportion. 3. Provide a 95% confidence interval for all the patient who are referred to the health center by the hospital. 4. What sample size would be required to estimate the proportion of all hospital referrals to the clinic with a margin of error of 0.04 at 95% confidence