Question

A die is toss three times let X be the sum of three numbers obtainedDetermine whether the random X has a binomial distribution if so take the number of trails N . If it doesn’t explain why

Answer 1

The given experiment is a die that is tossed three times.

X is the sum of the three numbers obtained.

You need to determine if the random X variable has a binomial distribution.

First, we need to understand what makes a random variable has a binomial distribution. There are 4 conditions to be met:

1. There are a fixed number of trials N

2. Each trial has only two possible outcomes: success or failure

3. The probability of success is equal in each trial

4. The trials are independent.

In this case, condition 1 is met, but condition 2 is not met, since in each trial we can obtain 6 different numbers, then there are not only two possible outcomes, but 6, then the sum of the three numbers has more than two possible outcomes. So, the random X variable doesn't have a binomial distribution.