What is the mean rainfall in inches for the four months with rainfall values 2, 4, 5, and 1?

• A. Two
• B. Three
• C. Three point five
• D. Four

Answer: (B)

The mean is the average value, found by adding all the numbers and dividing by how many values there are. For the rainfall amounts, add them up: 2 + 4 + 5 + 1 = 12. There are four months, so divide by 4: 12 ÷ 4 = 3. The mean rainfall is 3 inches, which represents the typical amount of rain across those four months.