1. Statistics a) Be able to find the averages called: MODE, MEDIAN & MEAN b) Be able to find the RANGE c) Know which is the best average to use for a given situation. Sunday, 20 March 2016

2. Statistics The MODE The most common number or item. The MODE of 2, 3, 4, 6, 3, 5, 3, 4, 7, 3 is 3 DataFrequency 0 – 20 2 – 45 4 – 63 6 – 82 The data has been put into a GROUPED frequency chart. 2 – 4 is the MODAL group

3. The MEDIAN The middle number To find the median of a) 2, 3, 3, 7, 8, 12, 8, 3, 6 b) 2, 3, 3, 7, 8, 12, 8, 3, 6, 10 Put the numbers into rank order 2, 3, 3, 3, 6, 7, 8, 8, 12 Find the centre number(s) 2, 3, 3, 3, 6, 7, 8, 8, 10, 12 If there are two numbers at the centre 2, 3, 3, 3, 6, 7, 8, 8, 10, 12 add these together and divide by 2 (6 + 7) ÷ 2 = 13 ÷ 2 = 6.5

4. The MEAN Add all the numbers together and then divide by the number of numbers. To find the mean of 3, 3, 6, 8, 1, 4, and 9 3 + 3 + 6 + 8 + 1 + 4 + 9 = 34 34 ÷ 7 = 4.86 The RANGE This is the difference between the smallest and largest numbers. The RANGE of 3, 3, 6, 8, 1, 4, and 9 is 9 – 1 = 8 There are 7 numbers

5. In each of the following questions, explain why you would use the MODE, MEDIAN or MEAN average 1)The GCSE results for a group C C C C D D D B D C C C 2)The wages of 10 people working in an office £150 £180 £190 £330 £120 £240 £450 £500 £125 £270 3)The average height of a group of people 4)The average amount of money spent by a Year 9 student during the weekend 5 ) The average number of days in a month