Question

Calculate the mean value (expected value) of the following discrete variable x (10 points):
x = 0, 1, 2, 3, 4, 5, 6
p(x) = 0.2, 0.2, 0.15, 0.15, 0.15, 0.1, 0.05

Answer 1

Answer:

Step-by-step explanation:

The mean of a discrete variable is found by pairing your x values with p(x) values. The summation formula looks like this:

$\sum x_{i}p_{i}$

Just in case that jogs your memory. But what I do is I go through one by one, take my first x value and multiply it by my first p(x) value, take my second and multiply those, etc. Create pairs then add all of that up like this:

E(x) = (0)(0.2) + (1)(0.2) + (2)(0.15) + (3)(0.15) + (4)(0.15) + (5)(0.1) + (6)(0.05)

E(x) = 2.35

So the expected value of x should be 2.35.