Mean, mode and median

Multiply each data value by its frequency and add the products. Divide this sum by the sum of all frequencies. This includes every repeated value.

Sort the data from smallest to greatest. With an odd number of values, the median is the middle value. With an even number, add the two middle values and divide by 2.

The mode is the most frequent data value. Find the greatest frequency in the frequency row, then select the corresponding data value. The answer is the value rather than its frequency.

Arithmetic mean = sum of all values ÷ number of values. Count every value, including repetitions. For example, the mean of 2, 4 and 9 is (2 + 4 + 9) ÷ 3 = 5.

The mode is the most frequent data value. Find the greatest frequency in the frequency row, then select the corresponding data value. The answer is the value rather than its frequency.

The total of four numbers equals their mean multiplied by 4. Subtract the sum of the three known numbers. Unknown number = 4 × mean − a − b − c.

Select the column for the requested club. Compare the two class counts in that column and find their difference.

The mode is the value that occurs most often in a data set.

1. Count how many times each number appears.
2. Find the number with the greatest frequency.

The data does not have to be sorted. The mode is not necessarily the largest number or the mean.

The range equals the greatest value minus the smallest value. Find these two extremes and subtract; there is no need to add intermediate values.

The median is the middle value of an ordered data set.

1. Arrange all numbers from smallest to largest.
2. When the number of values is odd, select the number exactly in the middle.

If there were an even number of values, calculate the arithmetic mean of the two middle values.