Question

6. 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 and 75. Find the: (i) Highest and the lowest marks obtained by the students. (ii) Range of the marks obtained. (iii) Mean marks obtained by the group.

Answer 1

$\bigstar$ Given:

• Marks (out of 100) obtained by a group of students in science test = 85, 76, 90, 85, 39, 48, 56, 95, 81 and 75

$\bigstar$ To Find:

• Highest and the lowest marks obtained by the students.
• Range of marks obtained.
• Mean marks obtained by the group.

$\bigstar$ Solution:

In order to find the highest and lowest marks, we have to arrange the marks in ascending order as follows:

Ascending order: 39, 48, 56, 75, 76, 81, 84, 85, 90, 95

1. The highest mark is 95 and the lowest is 39.
2. The range of the marks obtained = $(95-39)=56$
3. From the given information, we have,

Mean marks = $\sf\frac{Sum \: of \: the \: marks}{Total\: number \: of \: students}$

Mean marks = $(39 + 48 + 56 + 75 + 76 + 81 + 84 + 85 + 90 + 95)$ ÷ $10$

$\implies 729$ ÷ $10$

$\implies 72.9$

Hence, the mean mark of the students is 72.9.