_{In a sample of 400 registered voters, 192 were Republications. Develop a 95% confidence interval for the proportion of registered Republications in the population. a. What is the sample proportion? b. What z value should you use to calculate the margin of error: c. What is the margin of error? d. What is the confidence interval for the proportion of registered Republications in the population? e. There are 156 million registered voters in the US. Determine an interval for the number (how many) of registered Republications in the population}