Question
From a lot of 30 bulbs which include 6 defectives, a sample of 4 bulbs is drawn at random with replacement. Find the probability distribution of the number of defective bulbs.
Solution
There are 30 bulbs which include 6 defective bulbs.
Probability of getting a defective bulb =
Probability of getting a good bulbs =
Let X be random variable of defective bulbs in a sample of 4 bulbs.
X can take the values 0, 1, 2, 3, 4.
∴ probability distribution of defective bulbs is
Probability of getting a defective bulb =
Probability of getting a good bulbs =
Let X be random variable of defective bulbs in a sample of 4 bulbs.
X can take the values 0, 1, 2, 3, 4.
∴ probability distribution of defective bulbs is
