Show ALL work. If using a calculator, state the programs and commands you are using. Round answers to three decimal places where appropriate. A recent study found 66 American children, among 400 surveyed, have obesity. Answer the following questions based on a 96% confidence level. 1. Find the critical values. 2. What is the best guess for the proportion of American children that have obesity? 3. Find the confidence interval for the proportion of American children that have obesity. 4. How many children should be sampled so that the margin of error is 2 percentage points?