A study of 200 advertising firms revealed their income after taxes:
Income after Taxes Number of Firms
Under $1 million ......... 102
$1 million to $20 million....... 61
$20 million or more......... 37
a. What is the probability an advertising firm selected at random has under $1 million in income after taxes?
b. What is the probability an advertising firm selected at random has either an income between $1 million and $20 million, or an income of $20 million or more? What rule of probability was applied?