NCERT Class 7 Maths Chapter 3 Data and Handling Exercise 3.3

Chapter 3 Data and Handling Exercise 3.3

Question 1: Use the bar graph (Fig 3.3) to answer the following questions.
(a) Which is the most popular pet?
(b) How many students have dog as a pet?

Answer:
(i) Cat is the most popular pet.
(ii) 8 people have dogs as their pets.

Question 2: Read the bar graph (Fig 3.4) which shows the number of books sold by a bookstore during five consecutive years and answer the following questions:
(i) About how many books were sold in 1989? 1990? 1992?
(ii) In which year were about 475 books sold? About 225 books sold?
(iii) In which years were fewer than 250 books sold?
(iv) Can you explain how you would estimate the number of books sold in 1989?

Answer:
(i) In 1989, 180 books were sold. In 1990, 475 books were sold. In 1992, 225 books were sold.
(ii) In 1990, about 475 books were sold and in 1992, about 225 books were sold.
(iii) In 1989 and 1992 fewer than 250 books were sold.
(iv) 180 books were sold in 1989.

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

(a) How would you choose a scale?
(b) Answer the following questions:
(i) Which class has the maximum number of children? And the minimum?
(ii) Find the ratio of students of class sixth to the students of class eight.
Answer:

(a) We will take the scale as 1 unit = 10 children as we can represent a better and clear difference among the number of students of class 7th and class 9th.
(b)
(i) Class 5th has the maximum number of children while and class 7th has the minimum number of children.
(ii)
Total number of students in class 6th = 120
Total number of students in class 8th = 100
Ratio = ?
= 120/100 = 6/5
= 6:5

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:

(i) In which subject, has the child improved his performance the most?
(ii) In which subject is the improvement the least?
(iii) Has the performance gone down in any subject?
Answer:

(i) In Mathematics, the child improved his performance the most.
(ii) In Social Science, the child’s improvement least.
(iii) Yes, the performance of the child has gone down i.e. Hindi.

Question 5: Consider this data collected from a survey of a colony.
(i) Draw a double bar graph choosing an appropriate scale. What do you infer from the bar graph?
(ii) Which sport is most popular?
(iii) Which is more preferred, watching or participating in sports?
Answer:

(i) The graph is the double bar graph that represents the people who prefer either watching or participating in different sports.
(ii) Cricket is the most popular sport.
(iii) Watching sports has more preference, rather than participating in sports.

Question 6: Take the data giving the minimum and the maximum temperature of various cities given in the beginning of this Chapter (Table 3.1). Plot a double bar graph using the data and answer the following:
(i) Which city has the largest difference in the minimum and maximum temperature on the given date?
(ii) Which is the hottest city and which is the coldest city?
(iii) Name two cities where maximum temperature of one was less than the minimum temperature of the other.
(iv) Name the city which has the least difference between its minimum and the maximum temperature.
Answer:

(i) Jammu has the largest difference in the minimum and maximum temperature.
(ii) Jammu is the hottest city while Bangalore is the coldest city.
(iii) Bengaluru is having its maximum temperature 28°C is less than the minimum temperature 29°C in Ahmedabad. Bengaluru is having its maximum temperature 28°C is less than the maximum temperature 29°C in Jaipur.
(iv) Mumbai has the least difference between its minimum and the maximum temperature.