Statistics Class-8 RS Aggarwal ICSE Goyal Brothers Prakashan

Statistics Class-8 RS Aggarwal ICSE Goyal Brothers Prakashan Solutions Chapter-25. We provide step by step Solutions of Exercise / lesson-25 Statistics for ICSE Class-8  RS  Aggarwal Mathematics.

Our Solutions contain all type Questions of Exe-25 with Notes to develop skill and confidence. Visit official Website CISCE for detail information about ICSE Board Class-8 Mathematics.


–: Select Topics :–

Notes on Statistics 

Exe-25 ,


Notes on Statistics 

Introduction to Statistics

– A study dealing with the collection, presentation and interpretation and analysis of data is called as statistics

Data

  • Facts /figures numerical or otherwise collected for a definite purpose is called as data.
  • data collected first-hand data:- Primary
  • Secondary data: Data collected from a source that already had data stored

Frequency

– The number of times a particular instance occurs is called frequency in statistics.

Ungrouped data

Ungrouped data is data in its original or raw form. The observations are not classified in groups.

Grouped data

In grouped data, observations are organized in groups

Class Interval

  • The size of the class into which a particular data is divided.
  •    E.g divisions on a histogram or bar graph.
  • Class width = upper class limit – lower class limit

Regular and Irregular class interval

  • Regular class interval: When the class intervals are equal or of the same sizes.
  • E.g 0-10, 10-20, 20-30…..
  • Irregular class interval: When the class intervals are of varying sizes.
  • E.g 0-35, 35-45, 45-55,

Frequency table

– A frequency table or distribution shows the occurrence of a particular variable in a tabular form.

Sorting

  • Raw data needs to be sorted in order to carry out operations.-
  • Sorting ⇒ ascending order or descending order

Ungrouped frequency table

– When the frequency of each class interval is not arranged or organised in any manner

Grouped frequency table

– The frequencies of the corresponding class intervals are organised or arranged in a particular manner, either ascending or descending.


Exe-25 ,Statistics Class-8 RS Aggarwal ICSE Goyal Brothers Prakashan Solutions

Question 1:

Arrange the following data in ascending order:
(i) 8, 3, 11, 15, 1, 7, 16, 25, 9, 4
(ii) 5.7, 9.2, 3.1, 4.6, 1.8, 10.4, 2.5, 0.9, 1.2.

Answer :

(i) Ascending order is

1, 3, 4, 7, 8, 9, 11, 15, 16, 25

(ii) Ascending order is

0.9, 1.2, 1.8, 2.5, 3.1, 4.6, 5.7, 9.2, 10.4.

Question 2:

Arrange the following data in descending order:
(i) 15, 3, 0, 11,7, 2, 23, 14, 29, 5, 1, 17.
(ii) 23, 4.6, 1.2, 0.4, 3.5, 9.7, 6.1, 4.8, 0.8, 1.0.

Answer :

(i) Descending order is
29, 23, 17, 15, 14, 11. 7, 5, 3, 2, 1, 0.
(ii) Descending order is
9.7, 6.1, 4.8, 4.6, 3.5, 2.3, 1.2, 1.0, 0.8, 0.4.

Question 3:

Construct a frequency table for each of the following data:
(i) 3, 2, 5, 4, 1, 3, 2, 2, 5, 3, 1, 2, 1, 1, 2, 2, 3, 4, 5, 3, 1, 2, 3.
(ii) 7, 8, 6, 5, 6, 7, 7, 9, 8, 10, 7, 6, 7, 8, 8, 9, 10, 5, 7, 8, 7, 6.
(iii) 152, 165, 172, 144, 135, 156, 175, 140, 132, 150, 153, 147.
(iv) 13, 25, 19, 16, 8, 30, 27, 6, 0, 34, 40, 11, 4, 17.

Answer :

(i)

Rs aggrawal class 8 chapter 25_1

(ii)

Rs aggrawal class 8 chapter 25_2

(iii)

Rs aggrawal class 8 chapter 25_3

(iv)

Rs aggrawal class 8 chapter 25_4

Question 4:

Fill in the blanks:
(i) Lower limit of the class interval 14-22 is……………
(ii) Upper limit of the class interval 16-25 is…………..
(iii) Class-size of the class interval 20-30 is…………..
(iv) the upper and lower limits of a class interval be 18 and 11 respectively, then the class-interval is ………….

(v) If the lower and upper limits of a class interval be 11:5 and 21-5 respectively, then the class-
interval is………………

Answer :

(i) 14

(ii) 25

(iii) 10

(iv) 11-18

(v) 11.5-21.5

Question 5:

The marks out of 50. obtained by 30 students of a class in an examination are given below:
40, 12, 46, 37, 17, 27, 30, 6, 2, 23, 19, 39, 25, 5, 33, 19, 21, 12, 41, 17, 12, 19, 17, 8, 10, 1, 9, 21, 13, 48
Arrange them in ascending order and present it as a grouped data. by taking class-intervals
0-10, 10-20, 20-30, 30-40, 40-50.

Answer :

In Ascending order :
1, 2, 5, 6, 8, 9, 10, 12, 12, 12, 13, 17, 17, 17, 19, 19, 19, 21, 21, 23, 25, 27, 30, 33., 17. 39, 40, 41, 46, 48.

Rs aggrawal class 8 chapter 25_5

Question 6:

The fine imposed (in rupees) on 40 pupils for being absent is given below :
18, 8, 12, 6, 8, 16, 12, 5, 23, 2, 16, 23, 2, 10, 20, 12, 9, 7, 0, 5, 3, 6, 27, 21, 19, 15, 20, 24, 2, 16, 14, 8, 23, 24, 10, 14, 3, 8, 11, 2.
Present the data in the form of frequency distribution table by taking class intervals 0-5, 5-10, 10-15, 15-20, 20-25.

Answer :

Rs aggrawal class 8 chapter 25_6

P. Q. The weights in grams of 50 oranges are as follows:
126, 86, 70, 92, 11, 136, 141, 111, 107, 80, 110, 104, 118, 131, 113, 82, 75, 204. 81, 108, 100, 123, 90, 78, 90, 115, 110, 98, 106, 99, 107, 84, 76, 186, 82, 125, 123, 195, 68, 130, 128, 129, 139, 187, 93, 119, 115, 107, 115, 75.

From the grouped frequency table by taking class-intervals.

60-80, 80-100, 100-120, 12-140, 140-160, 160-180, 180-200, 200-220.

Answer :

Rs aggrawal class 8 chapter 25_7

Question 7:

The weights (in kg) of 30 students are given below:
48, 55, 30, 43, 41, 36, 48, 37, 34, 38, 46, 42, 38, 52, 37, 34, 40, 42, 50, 37, 35, 46, 42, 43, 37, 39, 45, 48, 46.

Form the grouped frequency table by taking class-intervals 30-35, 35-40, 40-45, 45-50, 50-55.

Answer :

Rs aggrawal class 8 chapter 25_8

Question 8:

The daily income (in rupees) of 30 workers is given below:
83, 96, 91, 80, 97, 111, 90, 83, 112, 120, 103, 77, 82, 90, 70, 68, 89, 85, 78, 105, 94, 97, 90, 89, 102, 113, 90, 106, 70, 84.

Construct a frequency table using groups 65-75, 75-85, 85-95, 95-105, 105-115, 115-125.

Answer :

Rs aggrawal class 8 chapter 25_9

Question 9:

The heights of 45 students measured to the nearest centimeter are given below:

155, 166, 159, 161, 158, 154, 153, 159, 157, 152, 160, 157. 158, 170, 152, 151, 162, 164, 171, 154, 165, 161, 150, 168, 162, 154, 160, 170, 163, 164, 165, 169, 165, 155, 157, 158, 160, 161, 156, 153. 150, 165, 167, 169, 172.

Prepare a frequency table taking the class intervals
150-155, 155-160, 160-165, 165-170, 170-175.

Answer :

Rs aggrawal class 8 chapter 25_10

Question 10:

Complete the table given below:

Rs aggrawal class 8 chapter 25_11

Answer :

Rs aggrawal class 8 chapter 25_12

Class-mark of 25-30 = (25 + 30)/2

= 55/2

= 27.5

Question 11:

Complete the table given below:

Rs aggrawal class 8 chapter 25_13

Answer :  

Rs aggrawal class 8 chapter 25_14

Class-mark of 26-30 = (26 + 30)/2

= 56/2

= 28

–: End of Statistics Class-8 RS Aggarwal Solutions :–

Return to- RS Aggarwal Solutions for ICSE Class-8 Goyal Brothers Prakashan


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