The Statistical Bulletin published by Metropolitan Life Insurance Co. reported that 2% of all American births result in twins. If a random sample of 8000 births is taken, find the mean, variance, and standard deviation of the number of births that would be result in twins.

Mean = 160 births

Variance = 156.8 births

Standard deviation = 12.522 births

Step-by-step explanation:

The mean number of births resulting in twins is given by the sample size (n=8000 births) multiplied by the probability of twins in any birth (p=2%).

In a binomial distribution like this one, the variance is given by:

The standard deviation is simply the square root of the variance:

the difference between a number and 5 is -2.

step-by-step explanation:

notice that the equation you are given has -2 (negative 2) on the right side, not 2. when you subtract 5 from a number n, you are finding the difference between the number and 5.

the difference between a number and 5 is -2.