Statistics: Mean, Median, Mode and Range Year 8 Advanced Maths class Statistics Lesson 2

The concepts Mean, median, mode and range are types of statistics. Statistics are used to describe or summarise a set of data. Mean, median, mode and range are types of statistics. Statistics are used to describe or summarise a set of data. Mean, median and mode are three different ways of finding a single number to represent the whole group. These three measures are used to show central tendency. Mean, median and mode are three different ways of finding a single number to represent the whole group. These three measures are used to show central tendency. Range looks at the spread of data. Range looks at the spread of data.

Mean The mean is a representative value for a set of data, e.g. if you took a test 5 times, the arithmetic mean of those 5 scores would be an indicator of your average performance. The mean is a representative value for a set of data, e.g. if you took a test 5 times, the arithmetic mean of those 5 scores would be an indicator of your average performance. It is a single number that you could use in place of all the different numbers in a data set and still get the same total. It is a single number that you could use in place of all the different numbers in a data set and still get the same total. The mean is calculated by adding each number or score in a data set and dividing the total by the number of numbers/scores. The mean is calculated by adding each number or score in a data set and dividing the total by the number of numbers/scores. Also known as “arithmetic average”. Also known as “arithmetic average”.

Median The middle value of an ordered set of values (or average of the middle two in a set with an even number of values). The middle value of an ordered set of values (or average of the middle two in a set with an even number of values). The value below which 50% of observations in a data set fall. The value below which 50% of observations in a data set fall. The median figure is useful when there are one or two observations among a small sample that are way out of the typical range (outliers). The median figure is useful when there are one or two observations among a small sample that are way out of the typical range (outliers).

Mode The number or score that occurs the most in a set of data. The number or score that occurs the most in a set of data. Indicates the most popular score or number. Indicates the most popular score or number. A data set may have more than one mode. A data set may have more than one mode.

Range The range of a set of scores is the difference between the highest and lowest scores. The range of a set of scores is the difference between the highest and lowest scores. It provides an indication of how the scores are spread or scattered. It provides an indication of how the scores are spread or scattered.

Why do we need to learn about these concepts? Learning about statistics and measures of central tendency can help with applying many other mathematical concepts and skills, such as problem solving, critical thinking, communication, developing number sense and applying computation. Learning about statistics and measures of central tendency can help with applying many other mathematical concepts and skills, such as problem solving, critical thinking, communication, developing number sense and applying computation. Statistics are encountered everyday all around us so we need to be able to understand and analyse them to be able to make informed decisions in day to day life. Statistics are encountered everyday all around us so we need to be able to understand and analyse them to be able to make informed decisions in day to day life.

Why? continued Information developed through the use of statistics enhances our understanding of how life works, helps us to learn about each other and helps individuals make informed decisions. Information developed through the use of statistics enhances our understanding of how life works, helps us to learn about each other and helps individuals make informed decisions. Statistics are widely used by government, business, the natural and social sciences, the media and many other sources. Statistics are widely used by government, business, the natural and social sciences, the media and many other sources. Mean – weather reports, test scores, sport, prices, measurements.Mean – weather reports, test scores, sport, prices, measurements. Median – sports scoring, house prices.Median – sports scoring, house prices. Mode – sales, opinion polls, merchandise selection.Mode – sales, opinion polls, merchandise selection. Range – test scores, weather.Range – test scores, weather.