Class 8 Bar Graphs and Histograms — practice questions with answers
Data Handling · 5 sample questions from the school syllabus. Try each one, then open the answer and the worked solution.
1. In a histogram, the bars are drawn for data grouped into what?
AClass intervals
BSingle values
CPercentages only
DPie sectors
Show answer
Answer: A) Class intervals
A histogram represents grouped (continuous) data, so each bar stands for a class interval.
2. The upper class limit of the interval 50-60 is:
A120
B54
C60
D66
Show answer
Answer: C) 60
The upper class limit is the larger value of the interval, which is 60.
3. Continuous class intervals like 0-10, 10-20 use the 'exclusive' method. In which class is the value 10 counted?
A10-20
B0-10
CBoth classes
DNeither class
Show answer
Answer: A) 10-20
In the exclusive method, the upper limit is not included; so 10 belongs to 10-20, not 0-10.
4. A histogram shows the number of hours 60 workers spent on a task, grouped as 0-2, 2-4, 4-6, 6-8 with frequencies 9, 21, 18, 12. The factory wants the percentage of workers who took less than 4 hours. Find this percentage.
A45
B55
C50
D100
Show answer
Answer: C) 50
Less than 4 hours: 9 + 21 = 30 of 60. Percentage = 6030×100=50%.
5. A histogram of the number of mangoes per tree in an orchard of 36 trees uses classes 20-30, 30-40, 40-50, 50-60. Frequencies are 6, 10, 14, 6. Estimate the total number of mangoes using the class mark of each class as the typical value per tree.