M M M R… Mean Median Mode Range
Dec 17, 2015
Let’s talk about the rules…
Every time you see RED font, write your answer on your dry erase board (or note card)
DO NOT hold up your answers until I ask you to
Question #1
What was the name of this lesson?
The “Golden Rule” of MMMR
When you get a set of data, the FIRST thing you should do is…
ARRANGE THE DATA IN NUMERICAL ORDER FROM SMALLEST TO LARGEST!
Ready to show me how smart you are?
Problem #2
Apply the “Golden Rule” of MMMR to the following: 3, 5, 6, 7, 2, 8, 4, 6
Brilliant!
2, 3, 4, 5, 6, 6, 7, 8
Alright, now that we have that out of the way…
Let’s talk about MEAN
Steps to find the MEAN
(Ex.) 6, 3, 6, 4, 4, 3, 7, 7
1. Apply the “Golden Rule” (just in case…)
3, 3, 4, 4, 6, 6, 7, 7
2. Add the numbers in the set
3 + 3 + 4 + 4 + 6 + 6 + 7 + 7 = 40
3. Divide by the total number in the set
40/8 = 5, so the MEAN is 5!
Who was paying attention?
Problem #3
What is a synonym for MEAN?
Problem #4
True or false?
The Mean of the set DOES NOT have to be one of the numbers in the set.
#3 Another name for MEAN is AVERAGE
#4 TRUE: “The mean of the set does not have to be one of the numbers in the set”
Remember the example we just did?The set was: 3, 3, 4, 4, 6, 6, 7, 7
The mean was 5.*Notice that 5 IS NOT one of the numbers in
the original set!
(Ex.) 3, 5, 2, 7, 5, 1, 8
Step #1 Apply the “Golden Rule”
1, 2, 3, 5, 5, 6, 7, 7, 8
Step #2 Count to find the middle number
1, 2, 3, 5, 5, 6, 7, 7, 8
So…5 is the MEDIAN
*Notice that there are EXACTLY 4 numbers to the right and 4 numbers to the left
(Ex.) 2, 3, 5, 1, 10, 8, 9
Step #1: Golden Rule
1, 2, 3, 5, 6, 8, 9, 10
Step #2: Find middle number
1, 2, 3, 5, 6, 8, 9, 10
Oh, no! There are TWO middle numbers!
Step #3: Find the AVERAGE of the middle numbers: (5 + 6)/2
MEDIAN = 5 1/2
Basically….
If the data set is an odd number, the middle number is the MEDIAN
(Ex.) 1, 2, 3, 4, 5
3 is the MEDIAN If the data set is an even number, there are
two middle numbers, so the MEDIAN is…
A data set can have ONE mode
(Ex.) 1, 2, 2, 3 Mode = 2
A data set can have MORE THAN ONE mode
(Ex.) 1, 1, 2, 2, 3 Mode = 1 and 2
A data set can have NO mode
(Ex.) 7, 3, 2, Mode = none
FIND THE MODE:
A) 6, 10, 22, 14, 15, 10, 13, 6, 17, 14
B) 5, 7, 3, 6, 8, 0, 1, 2, 11, 19, 4, 9, 12
C) 7, 3, 4, 8, 6, 4, 9, 2
Give me an R! A! N! G! E!
What’s that spell? RANGE!
Range is the difference between the largest number in the set and the smallest number in
the set.(Ex.) 4, 5, 10, 2
Golden Rule: 2, 4, 5, 10Subtract the smallest from the largest: 10 – 2
So, the RANGE is 8!