Lesson 2.2Describing Histogram Shape
Start hereWords, worked example, and sentence starters
Learning target I can make and read a histogram to display data in intervals.
Start hereWords for this lesson
Read each word before you begin. Say it out loud.
| Word | What it means | Example |
|---|---|---|
| HistogramSpanish: Histograma | A bar graph that groups data into equal ranges. The bars touch. | Bars side by side: 0-9 pts (3 players), 10-19 pts (8 players), 20-29 pts (4 players) |
| FrequencySpanish: Frecuencia | How many times a value shows up. | Bar height shows the count |
| IntervalSpanish: Intervalo | A range of numbers used to group data. | 0-9, 10-19, 20-29 are intervals of width 10 — each covers 10 values |
| DistributionSpanish: Distribución | How the data is spread out. | Most values near the peak |
| VariabilitySpanish: Variabilidad | How spread out the numbers are. | Data in just 2 intervals = low variability. Data across 6 intervals = high variability |
| Frequency tableSpanish: Tabla de frecuencias | A table that lists each interval and how many values fall in it. | 10–19 . . . 3 means three values are between 10 and 19. |
How it worksWorked examplereading the shape of a histogram
These numbers are not on your problems. The steps are. Follow them with your own numbers.
A histogram has a bar of height 2 over 60-69, height 4 over 70-79, and height 2 over 80-89.
- Sketch the bars at heights 2, 4, and 2 over the three intervals, touching with no gaps.
- Find the peak: the tallest bar covers the interval 70-79.
- Compare sides: the bar left of the peak and the bar right of it are the same height.
- Matching sides mean the data is nearly symmetric around the peak.
Answer: The histogram peaks over 70-79 and is symmetric, so a typical value falls in 70-79.
Now you trySame steps, your turn
The steps are the same as the worked example. The numbers are yours. Do the work.
A histogram has bars of height 1 over 400-409, height 4 over 410-419, height 3 over 420-429, and height 1 over 430-439.
- Sketch the four touching bars at the heights listed above.
- The peak covers the interval - .
- Bars left of the peak: Bars right of the peak: Do they match?
- The shape is (symmetric / not symmetric) because .
Say it and write itSentence starters
Finish each sentence out loud with a partner. Then use them in your writing.
- The peak of this histogram is the interval .
- Most of the values land between and .
- The shape is because the left side the right side.
- A typical value falls in the interval .
Word bank histogrampeakshapesymmetricintervalfrequencytypicalspreaddistributiontallestcompareside
Watch outA common mistake
A common mistake in Display Data: Histograms is counting a boundary value in two intervals at once — for example, putting the value 10 in both the '0–9' bin and the '10–19' bin. Each data value belongs to exactly ONE interval. Before you submit, add up all your frequencies and check that the total matches the number of data values you started with.
Lesson 2.2Describing Histogram Shape
Apply Day · Version ASupported practice
Learning target I can make and read a histogram to display data in intervals.
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1Complete each step, then write the final answer.
Data: 1, 4, 12, 13, 17, 25. Use intervals of 0–9, 10–19 and 20–29. What is the frequency of 0–9?
Show your workHint Count the values from 0 to 9.
Final answer: -
2Complete each step, then write the final answer.
A histogram has bars 0–9: 5, 10–19: 2 and 20–29: 3. How many values are there in all?
Show your workHint Each bar height is a count. Add the heights.
Final answer: -
3Complete each step, then write the final answer.
Data: 7, 15, 21, 22, 26, 28. Use intervals of 0–9, 10–19 and 20–29. What is the frequency of 20–29?
Show your workHint Count the values from 20 to 29.
Final answer:
Lesson 2.2Describing Histogram Shape
Apply Day · Version BCore practice
Learning target I can make and read a histogram to display data in intervals.
-
1Complete each step, then write the final answer.
Kim makes a histogram of 4, 10, 15, 19, 20, 27. She says the 10–19 bar has a height of 4. She counted 10, 15, 19 and 20. What is the correct height?
Show your workFinal answer: -
2Complete each step, then write the final answer.
Data: 19, 20, 20, 21, 29, 30, 38. Use intervals of 10–19, 20–29 and 30–39. What is the frequency of 20–29?
Show your workFinal answer: -
3Complete each step, then write the final answer.
Data: 6, 7, 11, 18, 24, 25, 29. Use intervals of 0–9, 10–19 and 20–29. What is the frequency of 20–29?
Show your workFinal answer:
Lesson 2.2Describing Histogram Shape
Apply Day · ChallengeExtension
Learning target I can make and read a histogram to display data in intervals.
-
1Circle the letter of the best answer. Show how you know.
A histogram has bars 0–9: 4, 10–19: 6 and 20–29: 2. Which statement must be true?
- A6 values are from 10 to 19.
- BOne value is exactly 15.
- CThe greatest value is 29.
- DThe data has only 3 values.
Show your work
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2Circle the letter of the best answer. Show how you know.
A histogram uses intervals 0–9, 10–19, 20–29, and 30–39. A data value of 19 belongs in which interval?
- A10–19
- B0–9
- C20–29
- DIt belongs in two intervals.
Show your work -
3Complete each step, then write the final answer.
Data: 8, 10, 13, 19, 20, 26, 30, 30. Use intervals of 0–9, 10–19, 20–29 and 30–39. What is the frequency of 10–19?
Show your workFinal answer: