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
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 meanIt is very easy to find!
Mean ExampleHere is an example test scores for Ms. Math’s class. 82 93 86 97 82To find the Mean, first you must add up all of the numbers. 82+93+86+97+82= 433Now, 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 86 78 79 86 93 97 In this case, the Median is 86!
Median Example #2 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 94This time, there are two numbers in the middle, 86 and 88 72 83 86 88 92 94Now 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
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
Now YOU try it!!! This is the Stat Family!Dad Mom Jack AlexKatie34 33 5 5 1
MeanHere are the ages again…Dad- 34, Mom- 33, Jack- 5, Alex- 5, Katie- 1What is the Mean?Remember… Mean is the AVERAGETry it on your paper and see what you come
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- 1What is the Median?Remember… Median is the MIDDLE NUMBERTry 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- 1What is the Mode?Remember… Mode is the MOST FREQUENTTry 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- 1What is the Range?Remember… Range is the DIFFERENCETry it on your paper and see what you come
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 1Now we need to subtract to find the difference 34-1= 33 The range is 33
To practice more, or to go for more help, then try some of these websites!http://www.bbc.co.uk/schools/revisewise/maths/http://www.mathgoodies.com/lessons/toc_vol8.shttp://math.about.com/library/weekly/aa020502a