Dot Plot Statistics Example 2

Follow the full solution, then compare it with the other examples linked below.

Example 2

medium
Two dot plots show test scores for Class A (scores clustered tightly around 75) and Class B (scores spread from 50 to 100). Both have the same median of 75. Compare the two distributions.

Solution

  1. 1
    Step 1: Centre: Both classes have the same median (75), so their centres are identical.
  2. 2
    Step 2: Spread: Class A's dots are tightly clustered (small range, low variability), while Class B's dots are widely spread (large range, high variability).
  3. 3
    Step 3: Shape: Class A likely appears symmetric and concentrated; Class B may appear more uniform or have a wider, flatter distribution.

Answer

Both classes have a median of 75, but Class A has low variability (clustered scores) while Class B has high variability (spread-out scores). Class A's performance is more consistent.
Dot plots allow visual comparison of centre, spread, and shape. Two distributions with the same centre can look very different due to variability. Consistent performance (tight clustering) is not the same as variable performance (wide spread) even when averages match.

About Dot Plot

A dot plot is a statistical chart that displays the frequency of data values using dots stacked above a number line. Each dot represents one observation, making it easy to see clusters, gaps, and the overall shape of a distribution for small to medium datasets.

Learn more about Dot Plot →

More Dot Plot Examples

Example 1 easy

The number of books students read last month: 0, 1, 2, 1, 3, 2, 1, 0, 2, 1, 4, 2. Create a dot plot

Example 3 medium

Create a dot plot for the data: 3, 5, 5, 6, 6, 6, 7, 8. What is the mode?

Example 4 medium

A dot plot shows ages of participants in a fun run: 20(3 dots), 25(5 dots), 30(8 dots), 35(6 dots),

Example 5 hard

A dot plot shows the number of absences for 20 students: 0(6), 1(5), 2(4), 3(2), 4(1), 8(1), 10(1).

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