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…

MeanMedianModeRange

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!

MeanThe mean is the Average of a

group of numbersIt 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 ExampleHere 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!

MedianThe 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 8678 79 86 93 97

In this case, the Median is 86!

Median Example #2Now, let’s try it with an even number of test scores.

92 86 94 83 72 88

First, we will put them in order72 83 86 88 92 94

This time, there are two numbers in the middle, 86 and 88

72 83 86 88 92 94

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

ModeThe 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 ExampleHere 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°

RangeThe 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 ExampleLet’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

Now YOU try it!!!This is the Stat Family!

Dad Mom Jack AlexKatie

34 33 5 5 1

MeanHere 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!

MeanRemember, 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

MedianHere 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!

MedianRemember, 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

ModeHere 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!

ModeRemember, 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

RangeHere 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!

RangeRemember, 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 difference34-1= 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