4.3.2 Hypergeometric Distribution

1. When units are selected from a finite population without replacement and the population consists of successes and failures.
2. The major difference between the Hypergeometric distribution and the Binomial distribution is that the probability of selecting a success is not constant and is not independent from each draw.

• X has a Hypergeometric distribution.
• x is the number of successes in the sample
• n is the sample size
• A is the number of successes in the population
• N is the population size
• N - A is the number of failures in the population
• n - x is the number of failures in the sample
• μ = E(X) =
• σ² = V (X) =
• is called the finite population correction factor.

• The number of spades selected when 5 cards are drawn from a standard 52 deck of cards.
• There are 20 Sony CD players in stock at the Sony store at the Mall Bangkapi; 5 are defective. A customer buys 6 of the 20 CD players. The number of defective CD players bought of the 6 CD players.
• The computer lab has 20 computers and 15 of the 20 computers have illegal software on them. The number of computers selected with illegal software from a sample of size 5.