RBSE Solutions for Class 7 Maths Chapter 3 Data Handling Intext Questions

Rajasthan Board RBSE Solutions for Class 7 Maths Chapter 3 Data Handling Intext Questions Textbook Exercise Questions and Answers.

RBSE Class 7 Maths Solutions Chapter 3 Data Handling Intext Questions

(Try These Page No: 59)

Question 1.
Weigh (in kg) at least 20 children (girls and boys) of your class. Organise the data and answer the following questions using this data:
(i) Who is the heaviest of all?
(ii) What is the most common weight?
(iii) What is the difference between your weight and that of your best friend?
Answer:
Weigh (in kg), of 20 children of my class are as follows :
30, 35, 35, 25, 20, 20, 18, 23, 35, 24, 28, 24, 30, 30, 25, 18, 23, 22,16, 30
(i) The highest weight is 35 kg.
(ii) The most common weight is 30 kg.
(iii) Do it yourself.

(Try These Page No: 61)

Question 1.
How would you find the average of your study hours for the whole week?
Answer:
First, I will find the study hours of all the 7 days of the week separately. Then, I will divide the sum of all these study hours by 7.

Question 2.
Find the mean of your sleeping hours during one week.
Answer:
Let my sleeping hours during week are as follows:

Day	Sleeping Hours
Monday	8
Tuesday	9
Wednesday	7
Thursday	8
Friday	7
Saturday	9
Sunday	8

Mean of sleeping hours
= \(\frac{8+9+7+8+7+9+8}{7}\) = \(\frac{56}{7}\) = 8 hours

Question 3.
Find atleast 5 numbers between \(\frac{1}{2}\) and \(\frac{1}{3}\).
Answer:
As we know that if a and b are any two rational numbers then their mean, i.e. \(\frac{a+b}{2}\) always lying between a and b, therefore,

(Try These Page No: 65)

Question 1.
Find the mode of:
(i) 2, 6, 5, 3, 0, 3, 4, 3, 2, 4, 5, 2, 4
Answer:
By arranging the data in tabular form, we get:

Here, number 2, 3 and 4 occurs 3 times. Therefore, they all are mode of the data.

(ii) 2, 14, 16, 12, 14, 14, 16, 14, 10, 14, 18, 14
Answer:
By arranging the values in tabular form, we get:

Here, the value 14 occurs maximum 6 times, hence 14 is the mode of the data.

(Think, Discuss and Write Page No: 65)

Question 1.
Can a set of number have more than one mode?
Answer:
Yes, set of number have more than one mode.

(Try These Page No: 65-66)

Question 1.
Find the mode of the following data:
12, 14, 12, 16, 15, 13, 14, 18, 19, 12, 14, 15, 16, 15, 16, 16, 15, 17, 13, 16, 16, 15, 15, 13, 15, 17, 15, 14, 15, 13, 15, 14
Answer:
Let us put this data in tabular form:

∵ 15 has occurred the highest number of times, therefore, 15 is the mode of the given data.

Question 2.
Heights (in cm) of 25 children are given below:
168, 165, 163, 160, 163, 161, 162, 164, 163, 162, 164, 163, 160, 163, 160, 165, 163, 162, 163, 164, 163, 160,165, 163, 162
What is the mode of their heights? What do we understand by mode here?
Answer:
Let's arrange the data in tabular form:

In the given data 163 has occurred the highest number of times, hence the mode of the data is 163 cm.
By mode we understand that most of the children have height 163 cm.

(Try These Page No: 67)

Question 1.
Your friend found the median and the mode of a given data. Describe and correct your friend's error if any :
35, 32, 35, 42, 38, 32, 34
Median = 42, Mode = 32
Answer:
To find median we arrange the data in ascending order:
32, 32, 34, 35, 35, 38, 42
Median = \(\left(\frac{7+1}{2}\right)^{t h}\) observation
= 4^th observation = 35
Mode : Here, observations 32 and 35 both occur maximum number of times, i.e. 2 times. Hence, mode = 32 and 35

(Try These Page No:71-72)

Question 1.
The bar graph shows the result of a survey to test water resistant watches made by different companies. Each of these companies claimed that their watches were water resistant. After a test the above results were revealed.

(a) Can you work out a fraction of the number of watches that leaked to the number tested for each company?
Answer:

(b) Could you tell on this basis which company has better watches?
Answer:
The company B has better watches.

Question 2.
Sale of English and Hindi books in the years 1995, 1996, 1997 and 1998 are given below:

Draw a double bar graph and answer the following questions:
(a) In which year was the difference in the sale of the two language books least?
(b) Can you say that the demand for English books rose faster? Justify.
Answer:
(a)


The difference in the sale of the two language books was least in the year 1998.

(b) Yes, we can say that the demand of English books rose faster.

(Try These Page No: 74)

Question 1.
Think of some situations, at least 3 examples of each that are certain to happen, some that are impossible and some that may or may not happen, i.e. situations that have some chance of happening.
Answer:
Situations, which are certain to happen:
(i) Sun rises in the east.
(ii) To throw a dice and get a number from 1 to 6.
(iii) Drawing a red ball from a bag containing red balls only.

Situations that are impossible to happen:
(i) To throw a dice and get a number 7.
(ii) Sun rises in the west.
(iii) Picking a green ball from a bag containing red balls only.

Situations that have some chances of happening:
(i) Tossing a coin and getting head.
(ii) To throw a dice and get 6.
(iii) Winning of match.

(Try These Page No: 75)

Question 1.
Toss a coin 100 times and record the data. Find the number of times heads and tails occur in it.
Answer:
By tossing a coin 100 times, we get: Head = 55 times,
Tail = 45 times

Question 2.
Aftaab threw a dice 250 times and got the following table. Draw a bar graph for this data.

Answer:

Question 3.
Throw a dice 100 times and record the data. Find the number of times 1, 2, 3, 4, 5, 6 occur.
Answer:
By throwing a dice 100 times, we get the data:

(Try These Page No: 76)

Question 1.
Construct or think of five situations where outcomes do not have equal chances.
Answer:

1. To draw a red card and face cards from a well shuffled deck of playing cards.
2. On tossing two coins together getting exactly one head and getting exactly two heads.
3. A bag having 60 non-defective bulbs and 40 defective bulbs. To take out a.non-defective bulb and defective bulb.
4. On throwing a dice, getting a number 6 or getting an even number.
5. A bag containing 4 red and 5 green bulbs. To take out red and green bulbs.