Averages and range · Grade 8
In Grade 8 you learn: comparing two sets of data.
An average is one number that represents a whole set of data. The mean shares the total out equally. The median is the middle value. The mode is the most common value. The range measures how spread out the data are.
Key facts
- Mean = total of the values ÷ number of values.
- Median: put the values in order. It is the middle one, or halfway between the middle two.
- Mode: the value that occurs most often. There can be more than one mode, or none.
- Range = largest value − smallest value.
Worked examples
Example 1
Find the mean, median, mode and range of 4, 8, 3, 8, 7.
Answer: Mean 6, median 7, mode 8, range 5
Example 2
Five quiz scores are 7, 9, 6, 8 and one more. The mean is 8. Find the missing score.
Answer: 10