from past experience it is known that 90 percent of one year

from past experience it is known that 90 percent of one year old children can distinguish their mother\'s voice from the voice of a similar sounding female a random sample of 20 one year olds are given this voice recognition test let the random variable x denote the number of children who do not recognize their mothers voice find the mean of x

Solution

sol)

probability=0.90

and sample size n=20

Now the Expected mean=np=20*0.90 =18