Q&A for How to Calculate the Mean

Convert the remainder to a decimal or fraction. For example: the average of 5, 12, and 17 is 34 ÷ 3, which is 11 with a remainder of 1. Convert the remainder to the fraction 1/3 or the decimal .33. Thus, the average is 11-1/3 or 11.33.

It is the number in a set which appears most often. In the set {1 7 9 0 4 5 4}, 4 is the mode.

The range of a data set is the difference between the largest number and the smallest number in the set.

That's fine. A mean does not have to be a whole number.

Add them all together and divide the answer by five (since there are five numbers).

Yes.

It works for all rational numbers.

No, the only way to find an exact mean is to add all the numbers together and then divide by the number of numbers. If you don't need an exact mean, you could make a quick estimate.

If some of the numbers in the set are negative, then the mean can surely be negative.

Yes, as it is still relevant to finding the average. For example, the mean of 1, 4, 0, and 6 is 2.75. This can be calculated by adding all four numbers and dividing by the number of values within the group.

Instead of using a remainder, keep dividing until you have one or more numbers after the decimal point. That gives you a more easily understood mean.

A mean (or average) tells you the trend or tendency of a set of numbers or data points.

Add the fractions and divide by 2. 2/5 + 5/6 = 12/30 + 25/30 = 37/30. 37/30 ÷ 2 = 37/60. That's the mean.

A "probability of 1" means that an event will definitely happen.

Add together all the numerical results, and divide by the number of papers.

"Average" is the same thing as "mean." Use the process shown above.

2 + 3 = 5. 80 / 5 = 16. (16)(2) = 32, so there are 32 adults running. (16)(3) = 48, so there are 48 children running. (32 + 48) = 80.) Total time running (adults and children) is (80)(3 min) = 240 min. Adult total time is (32)(120 + 7.5 sec) = (32)(127.5 sec) = 4,080 sec = 68 min. Total children time is 240 - 68 = 172 min. Mean time for children is 172 / 48 = 3.583 min.

Convert the remainder to either a fraction or a decimal, and it will be part of the mean. For example, 6½ is the mean of 5 and 8.

No, just one.

The mean is 35.5 +1.64 = 37.14. The number of data points (counting y) is 7. The sum of the data points is the mean multiplied by the number of data points, or (7)(37.14) = 259.98. We also know that the sum of the data points is 28 + 32 + 34 + 36 + 42 + 48 + y = (220 + y). So 220 + y = 259.98. Subtract 220 from both sides of that equation, and y = 39.98. (That's a strange answer, but it's appropriate given the strange condition that the mean is "1.64 more than 35.5.")

The mean is 35.5 + 1.64 = 37.14. That means (28 + 32 + 34 + 36 + 42 + 48 + y) / 7 = 37.14. So (220 + y) / 7 = 37.14. Then (220 + y) = (7)(37.14) = 259.98. So y = 259.98 - 220 = 39.98.

Add those numbers together and then divide by the number of numbers: the sum is 225. (Don't forget the -1 means to subtract 1.) There are 17 numbers. 225 / 17 = 13.235. (Even though the data points are all whole numbers, the mean does not have to be a whole number.)

See Calculate Standard Deviation .

Some means are not whole numbers. In this case the mean is 16/3 or 5 1/3.

First, add the numbers: 2 + 4 + 6 + 8 + 10 = 30. Then, divide the total by the number of values: 30 / 5 = 6. The mean is 6.

The range of a set of numbers is the difference between the largest number and the smallest number of the set. Just subtract the smallest number from the largest number.

See Find the Median of a Set of Numbers .

301 + 200 + 319 = 501 + 319 = 820. 820/3 = 273 r 1, or write it as 273 1/3, which is 273.3 repeating.

22.375 rounds to 22.4. The 7 in the thousandth place is 5 or more, so you raise the 3 to become a 4.

If you have five numbers, a, b, c, d, and e, the mean is (a + b + c + d + e) / 5.