ANSWER
1.75
EXPLANATION
The expected value of a discrete random variable X is,
[tex]E\lbrack X\rbrack=\sum x_iP(x_i)[/tex]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,
[tex]E\lbrack X\rbrack=0\cdot0.09+1\cdot0.36+2\cdot0.35+3\cdot0.13+4\cdot0.05+5\cdot0.02=1.75[/tex]Hence, the expected number of cars in the household is 1.75.