probability distribution

Question

The probability distribution for a random variable x is given in the table.

X: -10,-5,0,5,10,15,20

Probability: .20, .15, .05, .1, .25, .1, .15

find the probability that x≥5

Answer 1

Hi, Grace!

The table is showing you the possible values of the variable x and their corresponding probabilities. For example, the first column is telling you that the likelihood of x being equal to -10 is .20 (or 20 percent, of it helps to think of it that way :)

To find the probability that x is greater than or equal to 5, take a look at which values in the top row are 5 or greater. We can see that there are four: 5, 10, 15, and 20. To calculate the probability that x is one of these numbers, you simply add each of their corresponding probabilities from the second row of the table.

.1 + .25 + .1 + .15 = .6

I hope that helps!