Question 14 Marks
Activities like running or cycling reduce stress and the risk of menta disorders like depression. Running helps build endurance. Childrer develop stronger bones and muscles and are less prone to gain weight The physical education teacher of a school has decided to conduct an inte school running tournament in his school premises. The time taken by group of students to run 100 m , was noted as follows:

Based on the above, answer the following questions:
(i) What is the median class of the above given data ?
(ii) (a) Find the mean time taken by the students to finish the race.
OR
(b) Find the mode of the above given data.
(iii) How many students took time less than 60 seconds?

| Time (in seconds) | 0-20 | 20-40 | 40-60 | 60-80 | 80-100 |
| Number of students | 8 | 10 | 13 | 6 | 3 |
(i) What is the median class of the above given data ?
(ii) (a) Find the mean time taken by the students to finish the race.
OR
(b) Find the mode of the above given data.
(iii) How many students took time less than 60 seconds?
Answer
(i) Correct Cummulative Frequency
Median class $=40-60$
(ii) (a) Correct table for $x _{ i }$ and $f _{ i } x _{ i }$
$
\text { Mean }=\frac{1720}{40}=43
$
OR
(b) Modal class $=40-60$
$
\begin{aligned}
\text { Mode } & =40+\frac{(13-10)}{(26-10-6)} \times 20 \\
& =46
\end{aligned}
$
(iii) 31 students took time less than 60 seconds
View full question & answer→| Time (in sec) | Number of students (f) | Xi | cf | fi Xi |
| 0-20 | 8 | 10 | 8 | 80 |
| 20-40 | 10 | 30 | 18 | 300 |
| 40-60 | 13 | 50 | 31 | 650 |
| 60-80 | 6 | 70 | 37 | 420 |
| 80-100 | 3 | 90 | 40 | 270 |
| Total | 40 | 1720 |
Median class $=40-60$
(ii) (a) Correct table for $x _{ i }$ and $f _{ i } x _{ i }$
$
\text { Mean }=\frac{1720}{40}=43
$
OR
(b) Modal class $=40-60$
$
\begin{aligned}
\text { Mode } & =40+\frac{(13-10)}{(26-10-6)} \times 20 \\
& =46
\end{aligned}
$
(iii) 31 students took time less than 60 seconds

