Which of the following is a valid probability distribution?

Probability Distribution D

Step-by-step explanation:

We have to look at the general properties of a probability distribution to check the given probability distributions.

One of the main properties is:

"The sum of all probabilities should be equal to one."

The values are given at x-axis and probabilities are given along y-axis.

Lets look at the distributions one by one

Probability Distribution A:

The sum of all probabilities is 1.2 which makes it invalid

Probability Distribution B:

The sum of all probabilities is 1.6 which makes it invalid

Probability Distribution C:

The sum of probabilities is 0.9. Also not valid.

Probability Distribution D:

The sum of all probabilities is 1 so this distribution is valid ..

if you are saying purchasing 3 social media ads and one newspaper ad counts as one purchase then there are:

6 purchases

if you are asking how many of each then:

18 social media ads

6 newspaper ads