Question

It’s a statistics expected value question. The picture is attached. In addition to finding the expected value, I also need to find the variance, standard deviation, the value of P(X ≥ -1), and P(X ≤ -3).

Answer 1

The Solution:

Given:

Required:

Find the expected value of X.

The formula:

`E(x)=\sum_{i\mathop{=}-4}^0x_ip(x_i)`
`E(x)=-4(0.2)+-3(0.3)+-2(0.1)+-1(0.2)+0(0.2)`
`E(x)=-0.8-0.9-0.2-0.2+0=-2.1`

Thus,

Answer:

The expected value = -2.1