Mean, Median and Mode

1. Mean, Median and Mode A 6th Grade Math Presentation

2. What are mean, median and mode

3. Mean The mean is the average of a group of numbers. We get an average by adding the group of numbers together and dividing the total by their number. Example 1 + 4 + 9 + 11 + 5 = 30 and 30/5=6 The mean for this set of numbers is 6.

4. When would we use Mean Suppose you want to know what your numerical average is in Ms. Rufino�s math class. Let's say your grades so far are 80, 90, 92, and 78 on the four quizzes you have had. To find your quiz average, add up the four grades: 80 + 90 + 92 + 78 = 340 Then divide that answer by the number of grades that you started with, four: 340 / 4 = 85. So, your quiz average, or mean, is 85!

5. Now You Try!

6. Median The median is the middle number in a set of numbers when placed in numerical order. Example 1, 4, 5, 9, 11 In the above number set, the middle number, or median, is 5.

7. When would we use Median Suppose you are an adult looking for a job. You interview with a company that has ten employees, and the interviewer tells you that the average salary is $200 per day. Wow, that's a lot of money! But that's not what you would be making. For this particular company, you would make half of that. Each employee makes $100 per day, except for the owner, who makes $1100 per day. How do they get $200 for average then?! Well, let's take a look: Nine employees make $100, so adding those up is 9 x 100 = 900. Then the owner makes $1100, so the total is $1100 + $900 = $2000. Divide by the total number of employees, 10, and we have $2000/10 = $200. Because the owner makes so much more than everyone else, her salary "pulls" the average up. A better question to ask is, "What is the median salary?� To find the median salary, we look at the salaries in order: 100, 100, 100, 100, 100, 100, 100, 100, 100, 1100. This is an even number of salaries, so we look at the middle two. They are both 100, so the median is $100.

8. BUT WAIT! THERE�S A CATCH! What if there is an even amount of numbers in the set and there is no obvious median?! Look at the quiz grade example again: 90, 80, 92, 78. First list the numbers in order: 78, 80, 90, 92. The two middle ones are 80 and 90. So do we have two medians? No, we find the mean of those two: 80 + 90 = 170, and 170 / 2 = 85. So 85 is the median!

9. Now You Try!

10. Mode The mode is the number that occurs most often in a set of numbers. Example 2, 4, 5, 7, 7 The number that occurs most often, or the mode, in the above set of numbers is 7.

11. When would we use Mode Suppose you interview with a company that has 10 general employees, 7 assistants, 3 managers, and 1 owner. For this company, the mean salary is $400, and the median is also $400. But you are applying for the position of general employee, whose starting salary is $100! Why are the mean and median so far away? Well, the 10 general employees each make $100. The 7 assistants each make $400, the 3 managers each make $900, and the owner makes $1900. If you do the math to find the median or mean, $400 is the answer (try it!). So what can you do? The mode is the type of average you want to know in this situation. The mode is $100 because that number occurs ten times, which is more than any other number occurs.

12. Now You Try!

13. Gummy Bear Activity Using the bag of gummy bears that have been handed out to you, as a class we will complete the following activities to find mean, median and mode together!

14. How many gummy bears # of red gummy bears?

15. Find the Mean 2 red, 4 green, 5 yellow, 7 orange, 7 white 2 + 4 + 5 + 7 + 7 = 25 gummy bears 25/5 = 5 The mean of the gummy bears is 5.

16. Find the Median 2 red, 4 green, 5 yellow, 7 orange, 7 white  2, 4, 5, 7, 7 The median is 5.

17. Find the Mode 2 red, 4 green, 5 yellow, 7 orange, 7 white 2, 4, 5, 7, 7 The mode is 7.

18. Let�s Do a Quick Recap! http://www.youtube.com/watch?v=uydzT_WiRz4

19. Great Job Today Ladies and Gentlemen!!Thanks for being super students!

20. This presentation was made with by Ms. Rufino