1. Making a Line Plot Collect data and put in chronological order
Ex. Scores on a math test
Determine a scale and intervals
If you have a small range, you should probably use intervals of 1
With larger scales, it is best to mark intervals every 2, 5, or 10 numbers.
Ex. Scores on a math test
Use a scale from 60 to 100 and intervals of 5

2. Making a Line Plot Draw a horizontal line and mark the intervals
Ex. Scores on a math test

3. Making a Line Plot Mark an X above the number for each data point
If a number is repeated, place one X above the other
Ex. Scores on a math test X X X X X X X X X X X X X X X X X X X X X

4. Making a Line Plot
Count the number of data points and count the number of X’s to make sure you plotted each point!
Ex. Scores on a math test
22 data points X
22 X’s X X X X X X X X X X X X X X X X X X X X

5. Reading a Line Plot Understand the scale and interval
Ex. This line plot has intervals of 2, so an X that falls between numbers would represent the median of those numbers.
An X between the 6 and 8 would represent “7” X X X X X X X X X X X X X

6. Reading a Line Plot Finding the Minimum
Minimum – smallest value
The minimum is the number represented by the first X
The MINIMUM is 1 1 X X X X X X X X X X X X X
Do NOT just look at the numbers on the scale. The Minimum is NOT 0

7. Reading a Line Plot Finding the Maximum
Maximum – greatest value
The maximum is the number represented by the last X
The MAXIMUM is 15 X X 15 X X X X X X X X X X X
Do NOT just look at the numbers on the scale. The Maximum is NOT 16

8. Reading a Line Plot Finding the Range
Range – difference between highest value and lowest value
Subtract the number represented by the first X from the number represented by the last X -
= 14
The RANGE is 14 1 X X 15 X X X X X X X X X X X
Do NOT just look at the numbers on the scale. The Range is NOT 16 – 0 = 16

9. Reading a Line Plot Finding the Median
Median – middle number when data is arranged in chronological order
Cross off the first and last X. Continue crossing off the first and last X’s until you reach the middle.
The MEDIAN is 8 X X X X X X X X X X X X X

10. Reading a Line Plot Finding the Median
Median – middle number when data is arranged in chronological order
If there are 2 numbers left in the middle, the median is the middle of those 2 numbers.
The 2 middle numbers are 7 and 8, so the median is 7.5 X X X X X X X X X X X X

11. Reading a Line Plot Finding the Median
Median – middle number when data is arranged in chronological order
If you get confused crossing off the X’s, list the numbers represented by the X’s in chronological order and cross them off. X X X X X X X X X X X X X

12. Reading a Line Plot Finding the Mean
Mean – average
Add all the data points and divide by the total number of data points
Remember to include ALL the X’s
The MEAN is 7.5
Continue for all data points 4 X X 1 2 4 X 7 X X X X X X X X X X
Add Them Up!
Divide by the # of X’s + + + + 98
÷ 13
≈ 7.538
≈ 7.5
13 X’s so divide by 13
Round if you get a long decimal