Students can Download Chapter 3 Data Handling Ex 3.1, Question and Answers, Notes Pdf, KSEEB Solutions for Class 7 Maths, Karnataka State Board Solutions help you to revise complete Syllabus and score more marks in your examinations.

## Karnataka State Syllabus Class 7 Maths Chapter 3 Data Handling Ex 3.1

Question 1.

Find the range of heights of any ten students of your class.

Solution:

Students can try themselves.

(This is practical question)

Question 2.

Organise the following marks ion a class assessment, in a tabular form.

4, 6, 7, 5, 3, 5, 4, 5, 2, 6, 2, 5, 1, 9, 6, 5, 8, 4, 6, 7

i) Which number is the highest ?

Solution:

Highest number is 9

ii) Which number is the lowest ?

Solution:

Lowest number is 1

iii) What is the range of the data ?

Solution:

Range of the given data = Highest number – Lowest number = 9 – 1 = 8

iv) Find the arithmetic mean.

Solution:

Arithmetic Mean =

Question 3.

Find the mean of the first five whole numbers.

Solution:

The first whole numbers are 0, 1, 2, 3, 4

Arithemetic mean of five whole numbers =

Question 4.

A cricketer scores the following runs in eight innings :

58, 76, 40, 35, 46, 45, 0, 100. Find the mean score.

Solution:

The scores of 8 innings = 58, 76, 40, 35, 46, 45, 0, 100

Question 5.

Following table shows the points of each player scored in four games :

i) Find the mean to determine as average number of points scored per game.

Solution:

A’s average number of points scored

ii) To find the mean number of points per game for C, would you divide the total points by 3 or 4 ? Why ?

Solution:

To find the mean number of points per game for C, we shall divide the total points by 3 only because he did not play the 3rd game.

iii) B played in all the four games. How would you find the mean ?

Solution:

‘B’ played all the four games. So we find

iv) Who is the best performer ?

Solution:

To find out the best performer, we should know mean of all the 3 players. So we should calculate ‘C’s mean.

∴ The best performer is ‘A’

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:

Solution:

Marks obtained by a group (in ascending order) = 39, 48, 56, 75, 76, 81, 85, 85, 90, 95

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

Solution:

Highest and the lowest marks obtained by the student 95 and 39 respectively

ii) Range of the marks obtained.

Range = Highest score – Lowest score

= 95 -39 = 56

iii) Mean marks obtained by the group.

= 39 + 48 + 56 + 75 + 76 + 81 + 85 + 85 + 90 + 95

Question 7.

The enrollment in a school during six consecutive years was as follows :

1555, 1670, 1750, 2013, 2540, 2820. Find the mean enrollment of the school for this period.

Solution:

The enrollment in a school for 6 successive years } = 1555, 1670, 1750, 2013, 2540, 2820.

∴ Mean enrollment of the school for 6 years is 2,058

Question 8.

The rainfall (in mm) in a city on 7 days of a certain week was recorded as follows:

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

Solution:

Range of the rainfall = Highest Rainfall – Lowest Rainfall

= 20.5 – 0.0 = 20.5

ii) Find the mean rainfall for the week

Solution:

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

Solution:

No. of days of rainfall which was less than Mean rainfall } = 5 days

Question 9.

The heights of 10 girls were measured in cms and the results are as follows: 135, 150, 139, 128, 151, 132, 146, 149, 143, 141.

Solution:

The height of girls are arranged in ascending order} = 128, 132, 135, 139, 141, 143, 146, 149, 150, 151.

i) What is the height of the tallest girl?

Solution:

The height of the tallest girl is 151 cms

ii) What is the height of the shortest girl?

Solution:

The height of the shortest girl is 128cms

iii) What is the range of the data ?

Solution:

The range of the data = Highest height – lowest height

= 151 – 128 = 23

iv) What is the mean height of the girls?

Solution:

= 128 + 132 + 135 + 139 + 141 + 143 + 146 + 149 + 150 + 151

v) How many girls have heights more than the mean height.

Solution:

No. of girls who were more than mean height = 5