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Mean (expected value) of a discrete random variable

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A construction company is considering submitting bids for two contracts. It will cost the company $10,000 to prepare and submit the bids, and if won, each bid would produce $50,000 of income to the company. The company estimates that it has a 10% chance of winning any given bid.
Here is the probability distribution of X= the number of bids the company wins, and M= the amount of money the company profits from the bids.
X=# of bids won012
Calculate the mean of M.
  • Your answer should be
  • an integer, like 6
  • a simplified proper fraction, like 3/5
  • a simplified improper fraction, like 7/4
  • a mixed number, like 1 3/4
  • an exact decimal, like 0.75
  • a multiple of pi, like 12 pi or 2/3 pi