3. The Capital Asset Pricing Model (CAPM) is a financial model that assumes retums o portfolio are normally distributed. The variable in question is annual tu as a percentage of the money invested a return of 0% me the value of the portfoto does not change negative retum means that the porful loses money, and a positive retum means that the portfolio gains money Suppose a sample of 30 portfolios has an annual return of 14.7%, an average gain of 14.7%) with a standard deviation or ays Find and interpreti complete sentence) the 95% confidence interval of the mean annual return in all CAPM portfolios. 4. Suppose we want to estimate the height of all 3 grade boys in San Francisco. We want to create a 95% confidence interval that has a margin of error of at most 1.5 inches. Suppose we also have access to similar studies across the U.S. that shows that the standard deviation of population of 3 grade boys is 5 inches What is the minimum sample size we need to guarantee that our margin of error is at most 1.5 inches with a 95% confidence level? 5. A Gallup poll conducted Feb 17-28, 2020 asked 900 random American adults if they approve of the Affordable Care Act (aka Obamacare). This poll found 52% approved of the ACA. Find and interpret (in a complete sentence) the 90% confidence interval of the proportion of American adults who approve of the ACA in Feb 2020.