Paul is playing a game with his friend Peter where Paul tosses a coin and if it comes up heads Paul gives Peter a dollar and if it comes up tails Peter gives Paul a dollar. Paul plays the game ten times. a. What is the expected total earnings for Paul? b. What is the variance of Paul's total earnings? c. Suppose that the dice is biased and Paul has a 0.4 chance of winning for each flip. repeat the calculations in parts a and b?