A consumer magazine polls cell-phone-users to see if they are happy with their phones and would purchase the same model again. They randomly selected cell-phone-users and found the following: 429 of 550 owners of iPhones would purchase their phone again, and 324 of 450 owners of Androids would purchase the same phone again.

a) Find a 95% confidence interval (Two-Proportion z-Interval) for the difference in the proportions (1 points). b) Interpret your interval in the context of the problem. What does the confidence interval say about the difference in the satisfaction of the two types of owners? Hint: pay attention to the signs on the LB & UB (2 points). c) Conduct a hypothesis test with an alpha-level of 0.05 to determine if there is strong evidence that owners of iPhones are happier with their purchase than owners of Androids. Be sure to give the name of the test that you are performing (3 points). d) If your conclusion was wrong, what type of error occurred, Type I or Type II (1 point)?