A line plot (dot plot) shows the FREQUENCY of data

along a number line

• Each X or dot represents ONE data value

• Stack dots when values repeat

Step 1: Draw a number line with appropriate scale

Step 2: Mark each value from the data

Step 3: Place an X or dot above each value

Step 4: Stack X's when values repeat

Step 5: Add a title

Line plots work the same way with fractions!

Example: ½, ¼, ¾, 1½, 2¼

Just place them on a number line and mark frequency

Frequency = How many times a value appears

in a data set

Relative Frequency = Frequency ÷ Total

Often expressed as a DECIMAL or PERCENT

Data: Red=4, Blue=3, Green=3. Total=10

Bar graphs use rectangular BARS to show

CATEGORICAL DATA

• Height of bar = frequency or value

• Bars have GAPS between them

Regular Bar Graph: Shows frequencies or values

Percent Bar Graph: Shows data as percentages (total = 100%)

Double Bar Graph: Compares TWO sets of data side by side

Key Difference: Bar graphs have GAPS, histograms have NO GAPS!

Histograms show the frequency of

NUMERICAL DATA grouped into INTERVALS

• Bars touch each other (NO GAPS)

• X-axis shows continuous number ranges

Circle graphs show parts of a WHOLE

as slices of a circle

• Total circle = 360° or 100%

• Each slice represents a category

Central Angle = (Part ÷ Whole) × 360°

Percentage = (Part ÷ Whole) × 100%

Problem: 20 students prefer pizza, total 50 students. Find the angle and percentage.

Line graphs show how data CHANGES OVER TIME

• Points are connected with lines

• X-axis usually shows time

• Y-axis shows the measured value

Single Line Graph: Shows one set of data

Double Line Graph: Compares TWO sets of data over time

Line going UP: Data is increasing

Line going DOWN: Data is decreasing

Flat line: Data stays the same

Steep line: Rapid change

A stem-and-leaf plot organizes data by

splitting each number into STEM and LEAF

• Stem: Leading digit(s) - usually tens place

• Leaf: Trailing digit - usually ones place

Data: 23, 25, 27, 32, 34, 35, 41, 42

Box plots show the FIVE-NUMBER SUMMARY

of a data set

1. Minimum: Smallest value

2. Q1 (First Quartile): 25th percentile

3. Median (Q2): Middle value (50th percentile)

4. Q3 (Third Quartile): 75th percentile

5. Maximum: Largest value

Box: Shows the middle 50% of data (from Q1 to Q3)

Whiskers: Lines extending from box to min and max

IQR (Interquartile Range): Q3 − Q1

Outliers: Data points far from the rest (shown as dots)

IQR = Q3 − Q1

✓ Line plots: Use dots or X's on number line

✓ Frequency: How many times a value appears

✓ Relative frequency: Frequency ÷ Total (gives decimal or %)

✓ Bar graphs have GAPS, histograms have NO GAPS

✓ Circle graphs: Total = 360° or 100%

✓ Line graphs: Show change over TIME

✓ Stem-and-leaf: Stem = tens, Leaf = ones

✓ Box plot: Shows 5-number summary (min, Q1, median, Q3, max)

✓ IQR = Q3 − Q1 (middle 50% of data)

✓ Always label axes and add titles!

Bar Graph vs Histogram:

"Bar graphs have GAPS like spaces between CARS, Histograms touch like TRAIN CARS!"

Circle Graph Formula:

"Part over Whole times 360 - that's the angle you need to know!"

Relative Frequency:

"Frequency divided by Total - that's RELATIVE, it's quite vital!"

Stem-and-Leaf:

"STEM is the big number (tens), LEAF is the little one (ones)!"

Box Plot Quartiles:

"Q1 at 25%, Q2 (median) at 50%, Q3 at 75% - that's the way!"

Line Graph:

"Line goes up, line goes down - shows change over time around town!"