7. (20 points) A market researcher working for the credit card company wants to know if the distribution of applications by card is the same for the past three mailings. She takes a random sample of 200 from each mailing and counts the number applying for Silver, Gold, and Platinum. The data follow: Type of Card Silver Gold Platinum Mailing 1 57 50 42 Mailing 2 60 48 35 Mailing 3 58 55 38 Do a complete hypothesis test with a = 0.05.