Data is another word for information. In KS3 Maths you'll get plenty of practise handling data  analysing information, creating graphs or charts, designing questionnaires. This particular quiz is about averages in data handling and, more specifically, the median value.
There are three generally accepted ways to find the average in a set of data  the mean (the figure found by adding the totals together and then dividing by the number of totals used), the mode (the amount which appears most often) and the median. The median is the set of data which appears in the middle when the data is arranged from lowest to highest.
Though concentrating mainly on median values, this quiz also looks at ranges of values. The range is the difference between the highest and the lowest pieces of data. If you were to look at the number of pets Tom, Dick and Harry have. If Tom has 1, Dick has 2 and Harry has 6 the range would be 5 (6  1). The median would be 2 because this is the midmost figure.














Put the lowest at one end and the highest at the other. Then arrange all the others in between, in ascending order

Find this by adding the two middle values together then divide by 2. If both middle values are the same, that IS the median


(22 + 24) ÷ 2 = 23

This is qualitative data which cannot be arranged in size order, so there is no median


Largest = 19, smallest = 10, 19  10 = 9

In order: 10, 11, 12, 15, 17, 19. The median is halfway between 12 and 15. (12 + 15) ÷ 2 = 13.5


The median is lower because two smaller values have been added below the old median

The range is bigger because the largest and smallest values have both changed


Because it lies outside the region of most other values

A larger range shows the values are more spread out and more varied
