1. EQ: What are the measures of center and what is the measure of variability for a data set?
MCC6.SP3 and MCC6.SP.5

2. MEASURE OF CENTER
A single number that you can use to describe all the values in a data set.
A # that tells you roughly what the middle value in a data set is.
Mean, median, and mode

3. MEAN
The “average” or “fair share” value for the data. The mean is also the balance point of the corresponding data distribution.

4. MEAN (Average) How to Solve: Find the sum of the data.
Divide the sum by the number of pieces of data.

5. MEDIAN (middle)
The value for which half the numbers are larger and half are smaller. If there are two middle numbers, the median is the arithmetic mean of the two middle numbers.

6. MEDIAN (middle) 1) Order the data from least to greatest.
How to Solve:
1) Order the data from least to greatest.
2) Find the value in the middle.
*If there are two middle #’s, then add the two #’s and ÷ by 2, and that is your median.

7. MODE (most often)
The number that occurs the most often in a list. There can be more than one mode, or no mode

8. MODE (most often) How to Solve:
List the value(s) that occur most often.
If there is more than one value occurring the same number of times more than the other values, then both are modes.
There is no mode when all the values occur an equal # of times.

9. RANGE (SUBTRACT)
A measure of spread for a set of data.

10. RANGE (SUBTRACT)
To find the range, subtract the smallest value from the largest value in a set of data.

11. MEASURE OF VARIABILITY
A single number that can be used to describe an entire data set.
Describes how spread out the data is.
Range

12. OUTLIER
A value much greater or much less than the others in a data set.
Affects the mean more than it will affect the median.

13. EXAMPLE
Ms. Gray is 25 years old. She took a class with students who were 55, 52, 59, 61, 63, and 58 years old.
Ms. Grey’s age is an outlier because she is much younger than the others in the group.
OUTLIER

14. EXAMPLE
Use the following data set: , 20, 56, 47, 30, 18, 21.
1. Find the range. 2. Find the mean.
3. Find the median. 4. Find the mode.
5. Bonnie ran a mile in 8 minutes, 8 minutes, 7 minutes, 9 minutes, and 8 minutes. What was her mean time? 38 30 21 18
8 minutes