Question

Suppose the amounts of M&M's a machine dispenses into packages has a normal distribution with a mean of 25 M&M's and a standard deviation of 1 M&M. What is the probability that there are more than 26 M&M's?

Answer 1

16%

Explanation:

The mean is 25, and the standard deviation is 1.

26 is 1 standard deviation above the mean.

According to the empirical rule, 68% of the population is between -1 and +1 standard deviations. That means that 32% is less than -1 or greater than +1 standard deviations. So half of that, or 16%, is greater than +1 standard deviations.