# Ex.3.1 Q6 Data Handling - NCERT Maths Class 7

## Question

The marks (Out of $$100$$) obtained by a group of students in a science test are
$$85, 76, 90, 85, 39, 48, 56, 95, 81, 75.$$ Find the: -

(i) Highest and lowest marks obtained by the students.

(ii) Range of the marks obtained.

(iii) Mean marks obtained by the group.

Video Solution
Data Handling
Ex 3.1 | Question 6

## Text Solution

What is known?

Marks obtained by a group of students in a science test.

What is unknown?

Highest and lowest marks, Range of the marks, Mean marks

Reasoning:

Mean marks

\begin{align}=\frac{\text{Sum of marks}}{\text{Total no}\text{.of students}}\end{align}

Solution:

(i) Highest marks obtained by the student $$= 95$$
Lowest marks obtained by the student $$= 39$$

(ii) Range of the marks $$=$$ Highest marks $$–$$ Lowest marks

$$= 95\, – 39\\ = 56$$

Total no. of students $$= 10$$

Marks obtained by the group of students $$= 85, 76, 90, 85, 39, 48, 56, 95, 81, 75$$

Mean marks

\begin{align} &= \frac{{{\text{Sum of marks}}}}{{{\text{Total no }}{\text{.of students}}}}\\ &= \frac{{\left[ \begin{array}{l}85 + 76 + 90 + 85 + 39 +\\48 + 56 + 95 + 81 + 75\end{array} \right]}}{{10}}\\ &= \frac{{730}}{{10}}\\& = 73\end{align}

Thus, the mean marks obtained by a group of students are $$73.$$

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