Class 7 Maths

# Data Handling

## Exercise 3.3

Question 1: Use the bar graph to answer the following questions.

(a) Which is the most popular pet?
Answer: Cat

(b) How many students have dog as a pet?
Answer: 8

Question 2: Read the bar graph which shows the number of books sold by a bookstore during five consecutive years and answer the following questions:

(a) About how many books were sold in 1989? 1990? 1992?

Answer: 175 + 475 + 225 = 875

(b) In which year were about 475 books sold? About 225 books sold?

Answer: 1990 = 475 books and 1992 = 225 books

(c) In which years were fewer than 250 books sold?

Answer: 1989 and 1992

(d) Can you explain how you would estimate the number of books sold in 1989?

Answer: The bar is lower than 200 mark but a little higher than halfway mark between 100 and 200. Hence, it should be about 175

Question 3: Number of children in six different classes are given below. Represent the data on a bar graph.

ClassFifthSixthSeventhEighthNinthTenth
No. of children135120951009080

Answer:

(a) How would you choose a scale?

Answer: I will select each box as showing 20 students.

(b) Answer the following questions:

(i) Which class has the maximum number of children? And the minimum?

Answer: Fifth class has the maximum number of children, while tenth class has the minimum number of children.

(ii) Find the ratio of students of class sixth to the students of class eight.

Answer: Number of students in class sixth = 120

Number of students in class eighth = 100

Ratio = (120)/(100) = 3/4 = 3:4

Question 4: The performance of a student in 1st Term and 2nd Term is given. Draw a double bar graph choosing appropriate scale and answer the following:

SubjectsEnglishHindiMathsScienceS. Science
1st term (MM 100)6772888173
2nd term (MM 100)7065958575

Answer:

(a) In which subject, has the child improved his performance the most?

Answer: Maths

(b) In which subject is the improvement the least?

Answer: Social Science

(c) Has the performance gone down in any subject?

Answer:Yes, in Hindi

Question 5: Consider this data collected from a survey of a colony.

Favourite sportsCricketBasketballSwimmingHockeyAthletics
Watching1240470510430250
Participating620320320250105

(a) Draw a double bar graph choosing an appropriate scale.

Answer:

(b) What do you infer from the bar graph?

Answer: Number of people watching a sport is more than number of people participating in it.

(c) Which sport is most popular?

Answer: Cricket

(d) Which is more preferred, watching or participating in sports?

Answer: Watching a sport is more preferred than participating in it.