RS Aggarwal solution class 8 chapter 21 Data Handling Exercise 21C

Exercise 21C

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Q1 | Ex-21C | Class 8 | RS AGGARWAL | chapter 21 | Data Handling

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Question 1:

The top speeds of 30 different land animals have been organised into a frequency table given below:

Maximum speed (in km/h)	10–20	20–30	30–40	40–50	50–60	60–70
Number of animals	3	5	10	8	0	2

Draw a histogram for the given data.

Answer 1:

Q2 | Ex-21C | Class 8 | RS AGGARWAL | chapter 21 | Data Handling

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Question 2:

The ages (in years) of 360 patients treated in a hospital on a particular day are given below:

Age (in years)	10–20	20–30	30–40	40–50	50–60	60–70
Number of patients	90	40	60	20	120	30

Draw a histogram for the given data.
Hint. Take 10 small divisions = 10 patients.

Answer 2:

Q3 | Ex-21C | Class 8 | RS AGGARWAL | chapter 21 | Data Handling

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Question 3:

Draw a histogram for the frequency distribution of following data:

Class interval	8–13	13–18	18–23	23–28	28–33	33–38	38–43
Frequency	320	780	160	540	260	100	80

Hint. Take 1 small division = 10.

Answer 3:

Q4 | Ex-21C | Class 8 | RS AGGARWAL | chapter 21 | Data Handling

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Question 4:

Draw a histogram for the frequency distribution of the following data:

Class interval	20–25	25–30	30–35	35–40	40–45	45–50
Frequency	30	24	52	28	46	10

Answer 4:

Q5 | Ex-21C | Class 8 | RS AGGARWAL | chapter 21 | Data Handling

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Question 5:

Draw a histogram for the following data:

Class interval	600–640	640–680	680–720	720–760	760–800	800–840
Frequency	18	45	153	288	171	63

Hint. Take 1 small division = 3.

Answer 5:

ans

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Q6 | Ex-21C | Class 8 | RS AGGARWAL | chapter 21 | Data Handling

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Question 6:

The following table shows the number of illiterate persons in the age group (10–58 years) in a town. Represent the given data by means of a histogram.

Age group (in years)	10–18	18–26	26–34	34–42	42–50	50–58
Number of illiterate persons	175	325	100	150	250	525

Hint. Take 1 small division = 5 persons.

Answer 6:

Q7 | Ex-21C | Class 8 | RS AGGARWAL | chapter 21 | Data Handling

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Question 7:

The marks obtained (out of 20) by 30 students of a class in a test are given below:
7, 10, 8, 16, 13, 14, 15, 11, 18, 11, 15, 10, 7, 14, 20, 19, 15, 16, 14, 20, 10, 11, 14, 17, 13, 12, 15, 14, 16, 17.
Prepare a frequency distribution table for the above data using class intervals of equal width in which one class interval in 3–8 (including 2 and excluding 8). From the frequency distribution table so obtained, draw a histogram.

Answer 7:

Frequency distribution table

Marks	Tally Marks	Number of students
3-8	$\left|\right|$	2
8-13	$\cancel{\left|\right|\left|\right|}$ $\left|\right||$	8
13-18	$\cancel{\left|\right|\left|\right|}$ $\cancel{\left|\right|\left|\right|}$ $\cancel{\left|\right|\left|\right|}$ $|$	16
18-23	$\left|\right|\left|\right|$	4
Total =		30

Q8 | Ex-21C | Class 8 | RS AGGARWAL | chapter 21 | Data Handling

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Question 8:

The weights (in kg) of 30 students of a class are
39, 43, 32, 37, 29, 26, 31, 45, 46, 31, 37, 38, 30, 39, 36, 41, 35, 34, 41, 46, 39, 38, 36, 38, 40, 42, 33, 43, 44, 33.
Prepare a frequency distribution table using one class interval as 30–35, in which 30 is included and 35 excluded. Using the above data. draw a histogram.

Answer 8:

Frequency distriubution table 

Weight(in kg)	Tally Marks	Number of students
25-30	$\left|\right|$	2
30-35	$\cancel{\left|\right|\left|\right|}$ $\left|\right|$	7
35-40	$\cancel{\left|\right|\left|\right|}$ $\cancel{\left|\right|\left|\right|}$ $|$	11
40-45	$\cancel{\left|\right|\left|\right|}$ $\left|\right|$	7
45-50	$\left|\right||$	3
Total =		30

Q8 | Ex-21C | Class 8 | RS AGGARWAL | chapter 21 | Data Handling

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Question 9:

Look at the histogram given below and answer the question that follow:

(i)     How many students have height more than or equal to 135 cm but less than 150 cm?
(ii)    Which class interval has the least number of students?
(iii)   What is the class size?
(iv)    How many students have height less than 140 cm?

Answer 9:

(i) Number of students = $14+18+10=42$
(ii) Class interval with least number of students = 150−155
(iii) Class size = 130 − 125 = 5
(iv) Number of students with height less than 140 = $14+8+6=28$

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Q10 | Ex-21C | Class 8 | RS AGGARWAL | chapter 21 | Data Handling

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Question 10:

Look at the histogram given below and answer the question that follow:

(i)     What information is being given by the histogram?
(ii)    How many teachers are of age less than 45 years?
(iii)   How many teachers are of age 40 years or more but less than 55 years?

Answer 10:

 (i) The given histogram tells about the number of teachers in a school from the age group 25-30 to 55-60.
 (ii) Number of teachers with age less than 45 years = $3+5+7+6=21$
 (iii) Number of teachers with age more than 40 years but less than 55 years = $6+4+3=13$

Q11 | Ex-21C | Class 8 | RS AGGARWAL | chapter 21 | Data Handling

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Question 11:

The histogram given below shows the number of literate females in the age group of 10 to 40 years. Study the histogram carefully and answer the question that follow:

(i)     Write the classes, assuming that all the classes are of equal width.
(ii)    What is the class width?
(iii)   In which age group are the literate females the least?
(iv)   In which age group is the number of literate females the highest?

Hint. Number of class intervals of equal width = 6 (given), class width = $\frac{\left(40-10\right)}{6}=5.$

Answer 11:

(i) Age group =10 to 40
    Given all the classes are of equal width
    Number of class interval of equal width = 6
    Class width = $\frac{40-10}{6}=5$ 
    Classes are 10-15,15-20,20-25,25-30,30-35,35-40


(ii) Class width = $\frac{40-10}{6}=5$

(iii)Age group with least literate females = 10-15
(iv)Age group with highest literate females = 15-20