Binomial distribution: Examples

1. Ten coins are tossed simultaneously. Find the probability of getting at least 7 heads.

2. A die is tossed twice. Getting a number greater than 4 is considered a success. Find the mean and variance of the probability of number of success.

Solution,



3. Find the probability that in five tosses of a fair die, 3 will appear (i) twice, (ii) at most once, and (iii) at least two times.

Solution,



4. A coin is tossed for 7 times and the experiment is repeated for 128 times. Find the probability distribution. [Important]

Solution,

n=7; p = 1/2; q = 1/2



5. The incidence of occupational disease in an industry is such that workers have a 20% chance of suffering from it. What is the probability that out of six workers chosen at random, four or more will suffer the disease?

Solution,



6. The probability of a man hitting a target is 0.25. How many times must he fire so that the probability of hitting the target at least once is greater than 2/3?

Solution,