If an American household were chosen at random and asked how many tablet computers it owned, here are the probabilities as determined by a recent survey:

This is a legitimate assignment of probabilities because it satisfies these rules:
A) all the probabilities are between 0 and 1.
B) all the probabilities are between -1 and 1.
C) the sum of all the probabilities is exactly 1.
D) All the probabilities are between 0 and 1, and the sum of all the probabilities is exactly 1.
E) All the probabilities are between -1 and 1, and the sum of all the probabilities is exactly 1..

Question

If an American household were chosen at random and asked how many tablet computers it owned, here are the probabilities as determined by a recent survey:

This is a legitimate assignment of probabilities because it satisfies these rules:
A) all the probabilities are between 0 and 1. 
B) all the probabilities are between -1 and 1. 
C) the sum of all the probabilities is exactly 1. 
D) All the probabilities are between 0 and 1, and the sum of all the probabilities is exactly 1. 
E) All the probabilities are between -1 and 1, and the sum of all the probabilities is exactly 1..

Quizplus · Accepted Answer

The assignment of probabilities satisfies both rules A and C, meaning that all probabilities are between 0 and 1 and the sum of all probabilities is exactly 1. Rule B is not relevant to this situation as probabilities cannot be negative, which eliminates choice E. Therefore, the best choice is D, which is the most accurate description of the probabilities provided.

If an American Household Were Chosen at Random and Asked