Averages :
There are three types of average:
Mean- where you add up all the values and divide by how many there are.
Median- the middle value when all the data are arranged in order.
Mode- the most common occurring value
Why do we need three kinds of averages?
If you have a few extreme high values then the mean may be distorted. In those cases the median or mode may give you a better picture of the data. Averages
Averages Examples :
eg consider Averages Examples The mean is (1+1+3+4+10)÷5 = 3.8 The median is the middle value 3 and the mode is the commonest value 1 10 1 3 4 1
Interquartile :
eg consider Interquartile We know that the median divides the data into two halves. We also know that for a set of n ordered numbers the median is the (n + 1) ÷ 2 th value. Similarly, the lower quartile divides the bottom half of the data into two halves, and the upper quartile also divides the upper half of the data into two halves. Lower quartile is the (n + 1) ÷ 4 th value.
Upper quartile is the 3 (n + 1) ÷ 4 th th value. 11, 4, 6, 8, 3, 10, 8, 10, 4, 12 and 31
Interquartile :
eg consider Interquartile 11, 4, 6, 8, 3, 10, 8, 10, 4, 12 and 31 The first thing we do is order them low to high:- 3, 4, 4, 6, 8, 8,10, 10, 11, 12 ,31. Median (n+1)/2 LQ (n+1)/4 UQ 3(n+1)/4
M J Rollins :
M J Rollins muppetmasteruk