Line Plot (Dot Plot) Statistics Example 3

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

Example 3

medium
A line plot shows the weights of 12 apples in fractions of a pound: 14\frac{1}{4} (3 dots), 12\frac{1}{2} (5 dots), 34\frac{3}{4} (3 dots), 11 (1 dot). What is the mean weight of the apples?

Solution

  1. 1
    Step 1: Total weight = (14×3)+(12×5)+(34×3)+(1×1)=34+52+94+1=3+10+9+44=264=6.5(\frac{1}{4} \times 3) + (\frac{1}{2} \times 5) + (\frac{3}{4} \times 3) + (1 \times 1) = \frac{3}{4} + \frac{5}{2} + \frac{9}{4} + 1 = \frac{3 + 10 + 9 + 4}{4} = \frac{26}{4} = 6.5 pounds.
  2. 2
    Step 2: Mean = 6.512=1324≈0.54\frac{6.5}{12} = \frac{13}{24} \approx 0.54 pounds.

Answer

The mean weight is 1324≈0.54\frac{13}{24} \approx 0.54 pounds.
To find the mean from a line plot, multiply each value by its frequency, sum all the products to get the total, and then divide by the total number of data points. Line plots with fractional data require careful arithmetic with fractions.

About Line Plot (Dot Plot)

A line plot (also called a dot plot) is a diagram that displays data values as marks — usually X's or dots — stacked above their corresponding values on a number line. Each mark represents one data point, making it easy to see the frequency of each value.

Learn more about Line Plot (Dot Plot) →

More Line Plot (Dot Plot) Examples

Example 1 easy

Students measured the lengths of 10 leaves (in cm): 5, 6, 5, 7, 6, 5, 8, 6, 7, 5. Create a line plot

Example 2 medium

A line plot shows the number of hours students spent on homework: 1 hour (2 dots), 1.5 hours (4 dots

Example 4 hard

Two classes made line plots of their test scores. Class A: 70 (1), 75 (3), 80 (6), 85 (4), 90 (1). C

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