The mean is the mathematical average. The median is the middle value. The mode is the most repeated value. The range is the difference between the greatest and least value.
Mean: 13 Median: 12 Mode: 12 Range: 17
Practice makes perfect
We want to find the mean, median, mode and range of the given data set. Let's start by sorting the given values.
4 , 8 , 12 , 12 , 16 , 18 , 21
Mean
The mean of a data set is calculated by finding the sum of all of the values in the set and then dividing by the number of values. In this case, there are 7 values.
When the data are arranged in numerical order, the median is the middle value — or the mean of the two middle values — in a set of data. Let's arrange the given values and find the median.
4 , 8 , 12 , 12 , 16 , 18 , 21
The median of this set is 12.
Mode
The mode is the value or values that appear most often in a set of data.
Let's find the mode of the given values.
4 , 8 , 12 , 12 , 16 , 18 , 21
The value that appears most often is 12.
Mode: 12
Range
The range is the difference between the greatest and least values in a set of data. For our exercise, the greatest value is 21 and the least value is 4.
Range: 21- 4=17
