Parlay card betting. Odds makers try to predict which professional and college football teams will win and by how much (the spread). If the odds makers do this accurately, adding the spread to the underdog’s score should make the final score a tie. Suppose a bookie will give you $700000 for every $100000 you risk if you pick the winners in three different football games (adjusted by the spread) on a “parlay”

card. What is the bookie’s expected earnings per dollar wagered? Interpret this value.