There are 169 million registered voters in the us. determine an interval for the number (how many) of registered democrats in the population. + answer

Part A:

Given that in a sample of 400 registered voters, 204 were democrats, i.e. n = 400,

The 95% confidence interval for the proportion of registered democrats voters in the population is given by:



Part B:

Given that there are 169 million registered voters in the US, the interval for the number of registered democrats in the population is given by

[0.461(169,000,000), 0.559(169,000,000)] = (77,909,000, 94,471,000)

It is 6% because if you subtract 69-58=6 so 6% is the answer to your question.