🔵Understanding and Reading Line Plots
A line plot (also called a dot plot) is a graph that shows data along a number line. Each X above the number line represents one piece of data.
Key terms:
- Mode = most common value (where the most X's are)
- Range = largest value minus smallest value
- Total = each value multiplied by its count, then all added together
Line plots work with whole numbers AND fractions on the number line.
👀 See a worked example
🤖 Vidi's Key Points
- A line plot shows data using X marks above a number line
- Each X represents ONE piece of data
- The value with the most X's is the MODE (most common value)
- Always count all X's carefully to find the total
🟢Creating Line Plots from Data
How to Create a Line Plot:
- Step 1: Find the range — identify the smallest and largest values
- Step 2: Draw a number line with equal intervals covering all values
- Step 3: Label the number line (use fractions where needed)
- Step 4: Place one X above the number for each data point
- Step 5: Give the plot a clear title
Line plots with fractions often use intervals of 1/4 or 1/2.
👀 See a worked example
🤖 Vidi's Key Points
- First find the range (min and max values) before drawing
- Use equal intervals on the number line — fractions must be equally spaced
- Place one X for each data point — do not skip or double-count
- Always give the line plot a descriptive title and label the units
🟣Finding Totals and Differences from Line Plots
Line plots help us calculate quickly:
Finding Total: For each value, multiply it by the number of X's above it. Then add all products.
Finding Difference: Subtract the smallest value from the largest value shown on the plot.
Finding Average (Mean): Divide total by the number of data points (number of X's).
These skills apply to line plots with fractions too — multiply fractions by counts carefully!
👀 See a worked example
🤖 Vidi's Key Points
- Total = sum of (each value x number of X's at that value)
- Difference = largest value minus smallest value on the plot
- Mean = Total / number of data points
- With fractions: multiply fraction by count carefully, then add all products
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