Question

I need help with this question: Choose an American household at random. What is the expected number of cars for that household. Table: Number of cars, 0, 1,2, 3, 4, 5Probability: 0.09, 0.36, 0.35, 0.13, 0.05, 0.02

Answer 1

ANSWER

1.75

EXPLANATION

The expected value of a discrete random variable X is,

$E\lbrack X\rbrack=\sum x_iP(x_i)$

In this case, to find the expected number of cars for the household, we have to add all numbers of cars multiplied by their probabilities,

$E\lbrack X\rbrack=0\cdot0.09+1\cdot0.36+2\cdot0.35+3\cdot0.13+4\cdot0.05+5\cdot0.02=1.75$

Hence, the expected number of cars in the household is 1.75.