Recent content by mattamimi

1)the probability of 2 heads in 4 times ? 2)the probability of less than one head once? 3)the probability of more than 2 tails in 3 times ? 4)the expected number of two tails ? 5)the variance of the number of 2 heads

sorry,but I couldn't solve it,can you solve the first problem

thank you :) 1.) I think P(x)=4C1*(1/4)^1*(3/4)^3=0.421

by using binomial distribution if two coin are tossed 4 times ,find? 1)the probability of 2 heads in 4 times ? 2)the probability of less than one head once? 3)the probability of than 2 tails in 3 times ? 4)the expected number of two tails ? 5)the variance of the number of 2 heads?