Question

What is the probability of getting a 1 on a dice exactly 4 times in 20 flips? Give exact to 4 decimal places

Answer 1

Number of flips : n =20

Probability of getting a 1 on a dice on one flip : p = 1/6

q = 1-p = 1-1/6 = 5/6

X : Number of times getting a 1 on a dice in 20 flips

X follows Binomial distribution with n=20 and p=1/6

The probability mass function of X

P(X=r) : Probability of getting a 1 on a dice exactly 'r' times in 20 flips

Probability of getting a 1 on a dice exactly 4 times in 20 flips

Probability of getting a 1 on a dice exactly 4 times in 20 flips = 0.2022