Mean, Median, Mode and Range The Basics of Statistics

Did You Know… That you probably use Statistics such as Mean, Median, Mode and Range almost every day without even realizing it?!?

Today We Will Learn… Mean Median Mode Range And how to use these in everyday life, as well as the classroom!

To Help You Learn… You should have a Pencil, a Piece of Paper, and a Calculator if you need one.

What Do We Already Know? Sure, the words “Mean, Median, Mode and Range” all sound confusing… But what about the words we already know, like Average, Middle, Most Frequent, and Difference? They are all the same ideas!

Mean The mean is the Average of a group of numbers It is helpful to know the mean because then you can see which numbers are above and below the mean It is very easy to find!

Mean Example Here is an example test scores for Ms. Math’s class. 82 93 86 97 82 To find the Mean, first you must add up all of the numbers. 82+93+86+97+82= 433 Now, since there are 5 test scores, we will next divide the sum by 5. 440÷5= 88 The Mean is 88!

Median The Median is the middle value on the list. The first step is always to put the numbers in order.

Median Example First, let’s examine these five test scores. 78 93 86 97 79 We need to put them in order. 78 79 86 93 97 The number in the middle is 86 In this case, the Median is 86!

Median Example #2 Here the Median is 87 Now, let’s try it with an even number of test scores. 92 86 94 83 72 88 First, we will put them in order 72 83 86 88 92 94 This time, there are two numbers in the middle, 86 and 88 Now we will need to find the Average of these two numbers, by adding them and dividing by two. 86+88= 174 174÷2= 87 Here the Median is 87

Mode The Mode refers to the number that occurs the most frequently. It’s easy to remember… the first two numbers are the same! MOde and MOst Frequently!

Mode Example Here is an list of temperatures for one week. Mon. Tues. Wed. Thurs. Fri. Sat. Sun. 77° 79° 83° 77° 83° 77° 82° Again, We will put them in order. 77° 77° 77° 79° 82° 83° 83° 77° is the most frequent number, so the mode= 77°

Range The range is the difference between the highest and the lowest numbers of the series. All we have to do is put the numbers in order and subtract!

Range Example Let’s look at the temperatures again. 77° 77° 77° 79° 82° 83° 83° The highest number is 83, and the lowest is 77. All you need to do is subtract! 83-77= 6 In this case, the Range is 6

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Now YOU try it!!! This is the Stat Family! Dad Mom Jack Alex Katie 34 33 5 5 1

Mean Here are the ages again… Dad- 34, Mom- 33, Jack- 5, Alex- 5, Katie- 1 What is the Mean? Remember… Mean is the AVERAGE Try it on your paper and see what you come up with!

Then, since there are 6 people in the family, we next divide by 6. Mean Remember, to find the mean, we have to first add up all of the numbers. 34+33+5+5+1= 80 Then, since there are 6 people in the family, we next divide by 6. 78÷6= 13 The Mean in this case is 13

Median Here are the ages again… Dad- 34, Mom- 33, Jack- 5, Alex- 5, Katie- 1 What is the Median? Remember… Median is the MIDDLE NUMBER Try it on your paper and see what you come up with!

Median Remember, to find the mean, we have to first put all of the numbers in order. 34 33 5 5 1 The Mean in this case is 5

Mode Here are the ages again… Dad- 34, Mom- 33, Jack- 5, Alex- 5, Katie- 1 What is the Mode? Remember… Mode is the MOST FREQUENT Try it on your paper and see what you come up with!

Mode Remember, to find the mode, we have to first put all of the numbers in order. 34 33 5 5 1 The Mode in this case is 5

Range Here are the ages again… Dad- 34, Mom- 33, Jack- 5, Alex- 5, Katie- 1 What is the Range? Remember… Range is the DIFFERENCE Try it on your paper and see what you come up with!

Range Remember, to find the range, we have to first put all of the numbers in order. 34 33 5 5 1 The highest age is 34, and the lowest is 1 Now we need to subtract to find the difference 34-1= 33 The range is 33

Next, Try it at home with your Family!

To practice more, or to go for more help, then try some of these websites! http://www.bbc.co.uk/schools/revisewise/maths/data/12_act.shtml http://www.mathgoodies.com/lessons/toc_vol8.shtm http://math.about.com/library/weekly/aa020502a.htm