Please show working for each questions.

1. Decide whether the distribution is a probability distribution. Explain your reasoning. A) B) X 4 5 6 7 8 P(x) -1 P(x) 0.28 0.21 0.43 0.15 2. A state's department of transportation plans to develop a new section of interstate highway and receives 16 bids for the project. The state plans to hire four of the bidding companies. How many different combinations of four companies can be selected from the 16 bidding companies? 3. A coin is tossed and a die is rolled. Find the probability of tossing a head and then rolling a 6. 4. Forty-three race cars started the 2010 Daytona 500. How many ways can the cars finish, Second, and third