Histogram Statistics Example 4
Follow the full solution, then compare it with the other examples linked below.
Example 4
mediumA histogram shows frequencies 0–9 (2), 10–19 (5), 20–29 (9), 30–39 (7), 40–49 (1). How many observations are at least 20, and what is the modal class?
Solution
- 1 Step 1: Add the frequencies for intervals at least 20: observations.
- 2 Step 2: The tallest bar is 20–29 with frequency 9, so the modal class is 20–29.
Answer
There are observations at least 20, and the modal class is 20–29.
Histograms help us read grouped numerical data by interval. We can combine bars to answer range-based questions and identify the modal class by finding the tallest bar.
About Histogram
A histogram is a graph that groups numerical data into equal-width ranges (bins) and shows the frequency of values in each range using adjacent bars that touch. Unlike bar graphs, histograms display the distribution shape of continuous data.
Learn more about Histogram →More Histogram Examples
Example 1 medium
Test scores are grouped: 50–59 (4), 60–69 (8), 70–79 (12), 80–89 (6), 90–99 (2). Describe how to con
Example 2 mediumA histogram of student heights shows bars: 140–149 cm (3), 150–159 cm (10), 160–169 cm (15), 170–179
Example 3 mediumExplain two differences between a histogram and a bar graph.