Question

Distribution of height of students in a class VIII-E is given in the following table.

Height in cm (Class Marks)	120	130	140	150	160	170
No. of student	24	16	26	14	8	11

Build a histogram and find the class that has maximum number of students.

• A. 140 - 150
• B. 135 - 145
• C. 115 - 125
• D. 120 - 130

Answer 1

The correct option is B 135 - 145

First, we calculate the class interval from the class marks.

Difference between the two successive classes = h = 130 - 120 =10.

If x is the class marks then, lower and upper boundary of every class is x - $\frac{h}{2}$ and x + $\frac{h}{2}$.

Class marks (Height)	Frequency (No. of students)	Class intervals
120	24	115 - 125
130	16	125 - 135
140	26	135 - 145
150	14	145 - 155
160	8	155 - 165
170	11	165 - 175

Take suitable scale ,
On X-axis 1 division = 1 class interval
On Y-axis 1 division = 2 students

Now we plot the bar in the graph with respect to the class interval.



From the histogram, we can see that the length of the bar of class interval (135-145) is maximum.