Question

A math teacher has a number cube with faces numbered 1 through 6. He will roll the number cube 400 times. Which of the following ranges contains the best prediction for the number of times the number cube will land with a 1 or a 4 on the top face?

What is the answer and the steps to this question?

Answer 1

The probability of rolling a 1 or a 4 on a single roll of the number cube is 2/6, or 1/3. So the expected number of times the number cube will land with a 1 or a 4 on the top face after 400 rolls is 400 * 1/3 = 133.33.

The range that contains this expected value is roughly between 130 and 140, so a good prediction for the number of times the number cube will land with a 1 or a 4 on the top face is between 130 and 140.

Explanation: