Question

In 2010, among 121 randomly chosen voters polled 65 voted for Jerry Brown. In 2014, among 61 randomly chosen voters polled 36 voted for Jerry Brown. Assume you are interested in an 90% confidence interval for the difference between the corresponding true proportion of votes for Jerry Brown in the 2014 and 2010 elections.

Question 2: Choose the correct z-value or t-value that would be used in the 90% confidence interval for the difference between the corresponding true proportion of votes for Jerry Brown in the 2014 and 2010 elections.

Possible Answers: a) z = 2.576 b) z = 1.645 c) t = 2.660 d) t = 1.671 e) None of the above

Answer 1