# NCERT Class 7 Mathematics Solutions: Chapter 3 –Data Handling Exercise 3.1 Part 3

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1. The marks (out of ) obtained by a group of students in a science test are .

Find the:

(i) The highest and the lowest marks obtained by the students.

(ii) Range of the marks obtained.

(iii) Mean marks obtained by the group

Answer:

(i) Highest marks obtained by the student

Lowest marks obtained by the student

(ii) Range of marks Highest markslowest marks

(iii) Mean of obtained marks

So, the mean marks obtained by the group of students is .

2. The enrolment in a school during six consecutive years was as follows:

Find the mean enrolment of the school for this period.

Answer:

Mean enrolment

So, the mean enrolment of the school is

3. The rainfall (in mm) in a city on days of a certain week was recorded as follows:

Day | Mon | Tue | Wed | Thur | Fri | Sat | Sun |

Rainfall(in mm) |

(i) Find the range of the rainfall in the above data.

(ii) Find the mean rainfall for the week.

(iii) On how many days was the rainfall less than the mean rainfall?

Answer:

(i) The range of the rainfall Highest rainfall lowest rainfall

(ii) Main rainfall

(iii) days

i.e., Monday, Wednesday, Thursday, Saturday and Sunday rainfalls were less than the mean rainfall.