Question

the following table shows the probability distribution for the number of books a student typically buys at the annual book fair held at an elementary school. number of books 0 1 2 3 4 5 6 7 probability 0.35 0.20 0.15 0.10 0.07 0.08 0.04 0.01 let the random variable bb represent the number of books a student buys at the next book fair. what is the expected value of bb ?

Answer 1

Expected value of bb = 1.79

What is expectation?

At first it is important to know about probability of an event.

Probability gives us the information about how likely an event is going to occur

Probability is calculated by Number of favourable outcomes divided by the total number of outcomes.

Probability of any event is greater than or equal to zero and less than or equal to 1.

Probability of sure event is 1 and probability of unsure event is 0.

Suppose x is a random variable with the probability function f(x). suppose

$x_1, x _2, ..., x _ n$ are the values corrosponding to the actual occurance of the event and $p_1, p_2, ... , p_n$ be the corrosponding probabilities.

Expectation is given by the formula =

$p_1x_1 + p_2x_2 +....+ p_nx _n$

Expected value of bb =

0.35 ˣ 0 + 0.20 ˣ 1 + 0.15 ˣ 2 + 0.10 ˣ 3 + 0.07 ˣ 4 + 0.08 ˣ 5 + 0.04 ˣ 6 + 0.01 ˣ 7

0 + 0.20 + 0.30 + 0.30 + 0.28 + 0.40 + 0.24 + 0.07

= 1.79

To learn more about expectation, refer to the link:

brainly.com/question/24305645

#SPJ1