# Ex.3.1 Q2 Data Handling - NCERT Maths Class 7

Go back to  'Ex.3.1'

Organize the following marks in a class assessment, in a tabular form.

$$4, 6, 7, 5, 3, 5, 4, 5, 2, 6, 2, 5, 1, 9, 6, 5, 8, 4, 6, 7$$

(i) Which number is the highest?

(ii) Which number is the lowest?

(iii) What is the range of the data?

(iv) What is the arithmetic mean?

What is known?

Marks in class assessment.

What is unknown?

Highest marks,lowest marks,range,arithmetic mean.

Reasoning:

Range $$=$$ Highest marks $$-$$ lowest marks

Steps:

 S$$I$$ NO Marks Tally marks No. of students (Frequency) $$1$$ $$1$$ I $$1$$ $$2$$ $$2$$ II $$2$$ $$3$$ $$3$$ I $$1$$ $$4$$ $$4$$ III $$3$$ $$5$$ $$5$$ IIII $$5$$ $$6$$ $$6$$ IIII $$4$$ $$7$$ $$7$$ II $$2$$ $$8$$ $$8$$ I $$1$$ $$9$$ $$9$$ I $$1$$

The highest number is $$9.$$

The lowest number is $$1.$$

The range of the data $$=$$ Highest number $$-$$ Lowest number no.

$$= 9 \,– 1 = 8$$

$$\therefore$$ Mean of first five whole numbers

$= \frac{{{\text{Sum of all numbers}}}}{{{\text{Total numbers}}}}$

Arithmetic mean

\begin{align}& =\frac{\left[ \begin{align}& 4+6+7+5+3+5+4 \\ & +5+2+6+2+5+1+ \\ & 9+6+5+8+4+6+7 \\ \end{align} \right]}{20} \\ & =\frac{100}{20} \\ & =5\\ \end{align}

Video Solution
Data Handling
Ex 3.1 | Question 2

Learn from the best math teachers and top your exams

• Live one on one classroom and doubt clearing
• Practice worksheets in and after class for conceptual clarity
• Personalized curriculum to keep up with school