Mr. Jackson could think about his experiment a little differently. How many times should he expect to roll a 4 if he rolls his number cube 30 times? This is called the mean, or expected value. You can find it if you know the number of trials and the probability of success for an individual trial. Use the formula μx = np to find the expected value.

Find the expected value for the number of times you would roll a 4 in 30 rolls of a number cube.

How many trials, n, are there?
What is p, the probability of success for each trial?
What is the expected value of rolling a 4 in 30 rolls of a number cube?