Sums and Differences of Normally Distributed Variables Summary

Mean and Variance of the Sum of Random Variables

Summary

two or more random variables can be combined together by either adding or subtracting.

for adding two random variables the means and variances are added.

for subtracting two random variables the means are subtracted but the variances are added.

Key Skills

solve problems involving the mean and variance of the sums and differences of random variables, including word problems and applications.

Vocabulary

standard deviation, variance, random variable, independent events