A line plot shows the FREQUENCY of data

along a number line using X's or dots

• Each X represents one occurrence of a value

• Best for displaying small data sets (fewer than 25 values)

• Works well with whole numbers and fractions

Step 1: Draw a horizontal number line

Step 2: Mark all possible data values on the line

Step 3: Place an X above each value for each occurrence

Step 4: Label the number line and add a title

Data: Hours of sleep: 7, 8, 7, 6, 8, 7, 9, 7, 8

    X
    X   X
    X   X   X
6   7   8   9
Hours of Sleep
                

• Label the number line with fractions (e.g., 1/4, 1/2, 3/4)

• Plot data the same way as with whole numbers

• Useful for measurements (inches, cups, etc.)

A stem-and-leaf plot organizes numerical data

by splitting each number into a STEM and a LEAF

• STEM: Leading digit(s)

• LEAF: Last digit

• Keeps original data values visible

Step 1: Order the data from least to greatest

Step 2: Separate each number into stem (tens) and leaf (ones)

Step 3: List all stems in order (left column)

Step 4: Write corresponding leaves (right column)

Step 5: Include a key to explain the plot

Data: Test scores: 65, 72, 78, 81, 82, 85, 88, 90, 93

A bar graph uses RECTANGULAR BARS

to compare CATEGORICAL data

• Height or length of bar shows frequency or value

• Bars are separated by spaces

• Can be vertical or horizontal

Step 1: Draw horizontal and vertical axes

Step 2: Label axes (categories and frequency/value)

Step 3: Choose appropriate scale for values

Step 4: Draw bars with heights matching data values

Step 5: Add title and labels

Key Features:

• Bars do NOT touch each other

• Used for discrete/categorical data

• Easy to compare different categories

A histogram displays CONTINUOUS data

grouped into INTERVALS (bins)

• Similar to bar graph but for continuous data

• Bars TOUCH each other (no gaps)

• Shows distribution of data

Data: Test scores grouped in intervals

A frequency table organizes data

by showing how many times each value occurs

• Lists values or intervals in one column

• Shows frequency (count) in another column

• Foundation for creating many types of graphs

Simple Frequency Table: Individual values

Grouped Frequency Table: Data grouped into intervals

Relative Frequency: Shows proportions or percentages

Data: Favorite colors: Red, Blue, Red, Green, Blue, Red, Blue, Blue, Green

A circle graph shows how parts

relate to the WHOLE (100%)

• Circle divided into sectors (slices)

• Each sector represents a category

• Size of sector shows proportion of whole

Central Angle = (Part/Whole) × 360°

or

Central Angle = Percentage × 3.6°

Remember: A complete circle = 360°

All central angles must add up to 360°

Problem: 50 students were surveyed. 20 chose pizza, 15 chose burgers, 10 chose tacos, 5 chose salad. Find central angles.

A box plot displays the FIVE-NUMBER SUMMARY

of a data set

Shows distribution and spread of data at a glance

1. Minimum (smallest value)

2. Q₁ (Lower Quartile) - 25th percentile

3. Median (Q₂) - 50th percentile

4. Q₃ (Upper Quartile) - 75th percentile

5. Maximum (largest value)

IQR = Q₃ - Q₁

Interquartile Range (middle 50% of data)

Range = Maximum - Minimum

Total spread of data

• Left Whisker: From minimum to Q₁

• Box: From Q₁ to Q₃ (contains middle 50% of data)

• Median Line: Vertical line inside the box

• Right Whisker: From Q₃ to maximum

Data (ordered): 5, 7, 9, 11, 13, 15, 17, 19, 21

✓ Line Plot: Use X's, best for small data sets

✓ Stem-and-Leaf: Stem = tens, Leaf = ones, always include key

✓ Bar Graph: Bars separated, for categorical data

✓ Histogram: Bars touching, for continuous data intervals

✓ Frequency Table: Organize before creating graphs

✓ Circle Graph: Central angle = (part/whole) × 360°

✓ Box Plot: Shows minimum, Q₁, median, Q₃, maximum

✓ IQR: Interquartile Range = Q₃ - Q₁

✓ All angles in circle graph: Must add to 360°

✓ Always label: Title, axes, units, keys

Bar Graph vs Histogram:

"Bar graphs have gaps and show categories flat, Histograms touch with data that's continuous at that!"

Stem-and-Leaf:

"Stem holds the tens, leaf is the one - read them together and you're done!"

Circle Graph Central Angle:

"Part over whole times 360 - that's the angle that will be plenty!"

Box Plot Five Numbers:

"Min, Q1, Median too, Q3 and Max - that's your crew!"

Interquartile Range:

"Q3 minus Q1, IQR is done - middle fifty percent in one!"

Line Plot:

"Stack the X's high - count them to see frequency nearby!"