Problem 2: In a survey of 640 U.S. adults, 420 participants said they were taking vitamin E as a supplement. - Identify the variables [2 points] Show all the steps to construct the 90% confidence interval for the population proportion using a and z - score [4 points] - Write the conclusion using complete sentences [2 points] - Use the calculator option 1 - PropZInt to construct the confidence interval for the population proportion, if the confidence level will be 94%, and all other values stay the same [2 points] Find the minimum number of participants, if you want to be 98% confident that the estimated sample proportion is within ten percent of the true population proportion [2 points]