A local bank offers a money market fund that pays above average interest rates provided the investor maintains a minimum balance of $10,000. A vice president of the bank has a random sample of 200 accounts examined and their balances recorded (see data file "Money Market Mutual Fund").
a) Find the mean and the standard deviation of MMbal. Compute ranges in which at least 75% and 89% of the data will lie.
b) Determine how many observations actually fall outside the ranges computed in part a). Compare these to the minimum numbers expected by Chebysheff's inequality.