Question

The heights of $10$ students were measured in cm and the results are as follows :
$147,139,135,136,149,166,152,163,155,144$
(i) What is the range of the data?
(ii) What is the mean height of the students?
(iii) How many students are there whose height is more than the mean height?

• A. $30$; $100.5$; $3$
• B. $31$; $148.6$; $5$
• C. $32$; $149$; $5$
• D. $28$; $148.6$; $4$

Answer 1

The correct option is B $31$; $148.6$; $5$

Given,

The heights are: $147,139,135,136,149,166,152,163,155,144$.

Number of students $=10$.

(i) Here, the maximum value $=166$ and minimum value is $=135$.

We know,

Range $=$ Maximum value $-$ Minimum value
$=166-135=31$.

(ii) Mean height of students
$=$ $\frac{\text{Total height of students}}{\text{Number of students}}$

$=$ $\frac{147+139+135+136+149+166+152+163+155+144}{10}$
$=$ $\frac{1486}{10}$ $=148.6$.

(iii) Height of students more than the mean height are $149,166,152,163,155$.
i.e., $5$ student's height is more than mean height.

Hence, option $B$ is correct.