Suppose that you are a student worker in the statistics department and they agree to pay you using the random pay system. Each week, the Chair flips a coin. If it comes up heads, your pay for the week is $80 and if it comes up tails your pay for the week is $40. Your friend is working for the engineering department and makes $65 per week. The probability that your total earnings in 100 weeks are more than hers is approximately?