Question

The random variable X takes on the values of 2, 5, n, and 15. The probability distribution of X is shown in the following table

Answer 1

Answer:

12

Step-by-step explanation:

I did it on College Board

Answer 2

The question is missing some parts. Here is the complete question.

The random variable X takes on the values of 2, 5, n and 15. The probability distribution of X is shown in the table below.

The expected value of X is 9.1. What is the value of n?

a) 8

b) 8.52

c) 10

d) 12

e) 14.4

Answer: d) 12

Step-by-step explanation: In a probability distribution, Expected Value is the average (or mean) value a distribution can assume.

The Expected Value, E(X), can be determine by:

$E(X)=\Sigma xP(x)$

in which

x is how many times an event happens

P(x) is the probability of an event happening

The table below n is x and expected value is 9.1, then:

$9.1=2*0.1+5*0.4+0.2n+15*0.3$

$9.1=0.2n+6.7$

$0.2n=2.4$

n = 12

Value of n in this probability distribution is 12.