Simulating variance of sum of two binomial variables
In the last multiple choice exercise, you examined the expected value of the sum of two binomials. Here you'll estimate the variance.
This exercise is part of the course
Foundations of Probability in R
Exercise instructions
- Use your simulation of the variables X and Y to estimate the variance of
X + Y. - Use your simulation to estimate the variance of
3 * X + Y.
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
# Simulation from last exercise of 100,000 draws from X and Y
X <- rbinom(100000, 20, .3)
Y <- rbinom(100000, 40, .1)
# Find the variance of X + Y
# Find the variance of 3 * X + Y