General Motors wants to know if a newly designed car has a different appeal to people under 30 versus people over 50 (so they better know who to market the car towards). If there is at least a 10% difference in either proportion then GM will specifically design its marketing campaign towards that group (otherwise, they will target a more general audience). In another sample of 500 over-50, 375 expressed a favorable opinion of the car. In another sample of 450 under-30 year olds, 270 expressed a more favorable opinion of the new design (compared with the old design).

a) At the 5% level of significance does it appear there is at least a 10% difference?

b) What is the p-value?