Question

How many red and green cars will Pamela see on her way to work?

Answer 1

Given the table that shows the probability distribution of Pamela seeing red cars and green cars on her way to office, you need to remember that the formula for finding an Expected Value is:

$E(X)=\sum_^xP(x)$

Where "x" is an outcome and this is the probability of the outcome:

$P(x)$

• Using the formula and the values given in the exercise, you can set up that "X" is the number of red cards:

$E(X)=(0)(0.43)+(1)(0.31)+(2)(0.14)+(3)(0.10)+(4)(0.02)$

Evaluating, you get:

$E(X)\approx0.97\approx1$

• Using the formula and the values given in the exercise, you can set up that "X" is the number of green cards:

$E(X)=(0.45)(0)+(1)(0.17)+(2)(0.22)+(3)(0.07)+(4)(0.09)$

Evaluating, you obtain that:

$E(X)=1.18\approx1$

Hence, the answer is:

• 1 red car.

,

• 1 green car.