# GCSE Mathematics – Revision Notes Topic ‘Statistics and Numbers’

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**AQA - Statistics and Numbers**

Contents

9. Two way tables & Observation Sheets 29

11. Bar Charts and Pie charts 38

12 Frequency Distribution Tables and Cumulative frequency 44

# 1. Averages

The mode is the value that occurs most often.

The mode of 20,22,25,26,28,22,25,22,28,20,26,22 is 22 as it occurs the most amount of times in the sequence.

The median is the middle value when the values are arranged in order of size.

To get the median of 14,21,17,11,19,15,16 we must first rearrange our values in ascending order:

11,14,15,16,17,19,21

Our middle value of the sequence is 16 so this is our median.

If we are getting the median of an even number of values we must get the average of our middle two values.

To get the median of 34, 36, 30, 28, 42, 38, 33, 35 we first arrange in ascending order:

28, 30, 33, 34, 35, 36, 38, 42

Our middle values are 34 and 35 so our median is 34.5

The mean of a set of values is the sum of all the values divided by the number of values.

**Mean = **

To get the mean of 30, 28, 34, 37, 22 we add up all our values and divide by the number of values which in this case is 5.

Mean = = 30.2

The range or spread of a set of values is the difference between the highest value and the lowest value.

Range = Highest value - Lowest value

**Questions**

**1.1 Given the numb...**