A sample of 4 different calculators is randomly selected from a group containing 1212 that are defective and 3333 that have no defects. find the probability that at least one of the calculators is defective. round to the nearest thousandth.
There are 45C4 = 148,995 ways to choose 4 calculators out of a group of 45. There are 33C4 = 40,920 ways to choose 4 calculators that are not defective.
The probability that at least one is defective is (148,995 -40,920)/148,995 ≈ 0.725.
