4. According to the most recent poll result by Gallup Institute, published on July 23, 2021, (4c) Test your hypotheses with the significance level of a = 0.01. Justify all steps both "President Joe Biden's latest job approval rating of 50% is down from 56% in June." These algebraically and graphically. (10 points for the algebra and 5 points for the graph) results are based on, "telephone interviews conducted July 6-21, 2021, with a random sample of 1,007 adults, aged 18 and older, living in all 50 U.S. states and the District of Columbia." (4a) Estimate the 99% confidence interval of Joe Biden's approval rating. Justify all steps both algebraically and graphically. (10 points for the algebra and 5 points for the graph) (4d) The last month's approval rating of 56% came from, "telephone interviews conducted June 1-18, 2021, with a random sample of 1,012 adults, aged 18 and older, living in all 50 U.S. states and the District of Columbia." Do these survey results suggest President Biden's approval rating dropped during the past month? Set up hypotheses and test them with the (4b) Does this survey suggest President Biden's approval rating dropped from the previous significance level of a = 0.01. month's figure of 56%? Set up hypotheses. (5 points) Ho : Ha