# Statistics ML Aggarwal Class-9 ICSE Solutions Chapter-20

## Understanding APC ICSE Mathematics Solved Answer of Exercise-20 Statistics

**Statistics** is a collection of mathematical techniques that help to analyze and present data. Therefore we provide **Statistics **of **ML Aggarwal Class-9** ICSE Maths Solutions of Chapter-20 . Hence Step by step answer of Exercise-20.1 , Exercise-20.2, Exercise-20.3, MCQ and Chapter-Test of Exercise-20 Questions. So **Statistics** Solved Questions for **Class-9** of **ML** **Aggarwal** Understanding APC Mathematics are available here.

## Statistics ML Aggarwal Class-9 ICSE Maths Solutions Chapter-20

**–: Select Topics :–**

Note:- Before viewing Solutions of Chapter -20 **Statistics Class-9 **APC Understanding** ML** **Aggarwal** Solutions . Read the Chapter Carefully . Then solve all example given in Exercise-20.1 , Exercise-20.2, Exercise-20.3.Statistics ML Aggarwal Class-9 ICSE is important chapter.

**Exercise-20.1 Statistics Class-9 ICSE Understanding ML Aggarwal Solutions **

#### Question 1

Find the mean of 8, 6, 10, 12, 1, 3, 4, 4.

#### Answer 1

#### Question 2

5 people were asked about the time in a week they spend in doing social work in their community. They replied 10, 7, 13, 20 and 15 hours, respectively. Find the mean time in a week devoted by them for social work.

#### Answer 2

#### Question 3

The enrollment of a school during six consecutive years was as follows:

1620, 2060, 2540, 3250, 3500, 3710,

Find the mean enrollment.

#### Answer 3

#### Question 4

Find the mean of the first twelve natural numbers.

#### Answer 4

#### Question 5

(i) Find the mean of the first six prime numbers.

(ii) Find the mean of the first seven odd prime numbers.

#### Answer 5

#### Question 6

(i)The marks (out of 100) obtained by a group of students in a Mathematics test

are 81, 72, 90, 90, 85, 86, 70, 93 and 71. Find the mean marks obtained by the

group of students.

(ii) The mean of the age of three students Vijay, Rahul and Rakhi is 15 years. If their

ages are in the ratio 4 :5:6 respectively, then find their ages.

#### Answer 6

#### Question 7

– The mean of 5 numbers is 20. If one number is excluded, mean of the remaining

numbers becomes 23. Find the excluded number.

#### Answer 7

#### Question 8

The mean of 25 observations is 27. If one observation is included, the mean still remains 27. Find the included observation.

#### Answer 8

#### Question 9

The mean of 5 observations is 15. If the mean of first three observations is 14 and that

of the last three is 17, find the third observation.

#### Answer 9

#### Question 10

The mean of 8 variate is 10-5. If seven of them are 3, 15, 7, 19, 2, 17 and 8, then find

the 8th variate.

#### Answer 10

#### Question 11

The mean weight of 8 students is 45-5 kg. Two more students having weights 41-7 kg

and 53-3 kg join the group. What is the new mean weight?

#### Answer 11

#### Question 12

Mean of 9 observations was found to be 35. Later on, it was detected that an observation

81 was misread as 18. Find the correct mean of the observations.

#### Answer 12

#### Question 13

A student scored the following marks in 11 questions of a question paper :

7, 3, 4, 1, 5, 8, 2, 2, 5, 7, 6.

Find the median marks.

#### Answer 13

#### Question 14

Calculate the mean and the median of the numbers:

…………

#### Answer 14

#### Question 15

A group of students was given a special test in Mathematics. The test was completed

the various students in the following time in (minutes)

24, 30, 28, 17, 22, 36, 30, 19, 32, 18, 20, 24.

………….

#### Answer 15

#### Question 16

In a Science test given to a group of students, the marks scored by them (out of 100)are

1, 39, 52, 48, 54, 62, 46, 52, 40, 96, 42, 40, 98, 60, 52.

Find the mean and median of this data.

#### Answer 16

#### Question 17

The points scored by a Kabaddi team in a series of matches are as follow

17, 2, 5, 27. 15. 8. 14, 10, 48, 10, 7, 24, 8, 28, 18.

Find the mean and the median of the points scored by the Kabaddi team

#### Answer 17

#### Question 18

The following observations have been arranged in ascending order. If the median

the data is 47-5, find the value of x.

17, 21, 23, 29, 39, 40, x, 50, 51, 54, 59, 67, 91, 93

#### Answer 18

#### Question 19

The following observations have been arranged in ascending order. If the median

the data is 13, find the value of x: ….. 0S

3, 6, 7, 10, x, x + 4, 19, 20, 25, 28.

#### Answer 19

**EXERCISE – 20.2 Statistics ML Aggarwal Class-9 ICSE Understanding APC Solved Questions**

#### Question 1

State which of the following variables are continuous and which are discrete:

(i)marks scored (out of 50) in a test.

(ii) daily temperature of your city.

(iii) sizes of shoes.

(iv)distance travelled by a man.

(v)time.

#### Answer 1

#### Question 2

Using class intervals 0-4, 5 -9, 10-14,

following data :

13, 6, 10, 5, 11, 14, 2, 8, 15, 16, 9, 13, 17, 11, 19, 5, 7, 12, 20, 21, 18, 1, 8, 12, 18.

#### Answer 2

#### Question 3

Given below are the marks obtained by 27 students in a test:

21, 3, 28, 38, 6, 40, 20, 26, 9, 8, 14, 18, 20, 16, 17, 10, 8, 5, 22, 27, 34, 2, 35, 31, 16, 28, 37.

………………….

#### Answer 3

#### Question 4

A Explain the meaning of the following terms :

(i) variate

(ii) class size

(iii) class mark

(iv) class limits

(v) true class limits

(vi) frequency of a class

(vii) cumulative frequency of a class.

#### Answer 4

#### Question 5

Fill in the blanks :

(i) The number of observations in a particular class is called ……of the class.

(ii) The difference between the class marks of two consecutive classes is the

of the class.

(iii) The range of the data 16, 19, 23, 13, 11, 25, 18 is.. .

(iv) The mid-point of the class interval is called its …

(v) The class mark of the class 4 – 9 is ….

#### Answer 5

#### Question 6

The marks obtained (out of 50) by 40 students in a test are given below:

28, 31, 45, 03, 05, 18, 35, 46, 49, 17, 10, 28, 31, 36, 40, 44, 47, 13, 19, 25, 24, 31, 38, 32,

27, 19, 25, 28, 48, 15, 18, 31, 37, 46, 06, 01, 20, 10, 45, 02.

(i) Taking class intervals 1- 10, 11 – 20, .., construct a tally chart and a frequency

distribution table.

at

(ii) Convert the above distribution to continuous distribution.

(iii) State the true class limits of the third class.

(iv) State the class mark of the fourth class.

#### Answer 6

#### Question 7

Use the adjoining table to find:

(i) upper and lower limits of fifth class.

…..

(ii) true class limits of the fifth class.

…..

(iii) class boundaries of the third class.

…..

(iv) class mark of the fourth class.

…..

…………………………….

#### Answer 7

#### Question 8

The marks of 200 students in a test were recorded as follows:……………..

#### Answer 8

#### Question 9

Given below are the marks secured by 35 students in a test:

41, 32, 35, 21, 11, 47, 42, 00, 05, 18, 25, 24, 29, 38, 30, 04, 14, 24, 34, 44, 48, 33, 36, 38

41, 46, 08, 34, 39, 11, 13, 27, 26, 43, 03.

Taking class intervals 0-10, 10– 20, 20 – 30.

frequency distribution table. Find the number of students obtaining below 20 marks

#### Answer 9

#### Question 10

The marks out of 100 of 50 students in a test are given below:

…………

(i) Taking a class interval of size 10, construct a frequency as well as cumulative

frequency table for the given data.

(ii) Which class has the largest frequency?

(tii) How many students score less than 40 marks?

(iv) How many students score first division (60% or more) marks?

#### Answer 10

#### Question 11

Construct the frequency distribution table from the following data:………………

State the number of children in the age group 10 – 13.

#### Answer 11

#### Question 12

Rewrite the following cumulative frequency distribution into frequency distribution:

……………….

#### Answer 12

#### Question 13

The water bills (in rupees) of 32 houses in a locality are given below. Construct a

frequency distribution table with a class size of 10.

80, 48, 52, 78, 103, 85, 37, 94, 72, 73, 66, 52, 92, 85, 78, 81, 64, 60, 75, 78, 108, 63, 71, 54,

59, 75, 100, 103, 35, 89, 95, 73.

#### Answer 13

#### Question 14

The maximum temperatures (in degree celsius) for Delhi for the month of April, 2014,

as reported by the Meteorological Department, are given below:

……………….

#### Answer 14

#### Question 15

(i) The class marks of a distribution are 9-5, 16-5, 23-5, 30-5, 37-5 and 44-5. Determine

the class size and the class limits of the third class.

………………

#### Answer 15

### EXERCISE – 20.3 **Solutions of ML Aggarwal **

#### Question 1

The……………….was

#### Answer 1

#### Question 2

The…………………….follows.

#### Answer 2

#### Question 3

Given…………………………years.

#### Answer 3

#### Question 4

Birth……………………….is.

#### Answer 4

#### Question 5

Given…………………school.

#### Answer 5

#### Question 6

Draw…………………………data.

#### Answer 6

#### Question 7

Draw………………factory.

#### Answer 7

#### Question 8

Draw…………………………data.

#### Answer 8

#### Question 9

Draw………………..distribution.

#### Answer 9

#### Question 10

D

#### Answer 10

#### Question 11

Draw…………………….data.

#### Answer 11

#### Question 12

In…………..under.

#### Answer 12

#### Question 13

Draw…………………….data.

#### Answer 13

#### Question 14

In…………………………table.

#### Answer 14

#### Question 15

Draw…………………….data.

#### Answer 15

#### Question 16

In………………….obtained.

#### Answer 16

#### Question 17

The……………….73.

#### Answer 17

#### Question 18

The……………..distribution.

#### Answer 18

#### Question 19

The…………….distribution.

#### Answer 19

#### Question 20

The…………….below.

#### Answer 2

** MCQ of Exercise-20 Statistics ML Aggarwal ICSE Class-9 Solutions**

#### Question 1

.The marks obtained by 17 students in a mathematics test (out of 100) are given

below:

91, 82, 100, 100, 96, 65, 82, 76, 79,90, 46, 64, 72, 66, 68, 48, 49

The range of the data is

(b) 54

(a) 46

(d) 100

#### Answer 1

#### Question 2

The class mark of the class 90-120 is

(b) 105

(c) 115

(d) 120

Answer 2

#### Question 3

In a frequency distribution, the mid-value of a class is 10 and the width of the class

is 6. The lower limit of the class is

(b) 7

(c) 8

(d) 12

#### Answer 3

#### Question 4

The width of each of 5 continuous classes in a frequency distribution is 5 and the lower

limit of the lowest class is 10. The upper limit of the highest class is

(a) 15

(b) 25

(c) 35………..

#### Answer 4

#### Question 5

The class marks of a frequency distribution are given as follows:

15, 20, 25, ……

The class corresponding to the class mark 20 is

…………………

#### Answer 5

#### Question 6

In the class intervals 10 – 20, 20 – 30, the number 20 is included in

(a) 10-20

(b) 20 – 30

……………………

#### Answer 6

#### Question 7

A grouped frequency distribution table with class intervals of equal size …………

250 270 (270 not included in this interval) as one of the class intervals is constructed……….

268, 220, 368, 258, 242, 310, 272, 342, 310, 290, 300, 320, 319, 304, 402, 318, 406 ………..

#### Answer 7

#### Question 8

The mean of x- 1, x + 1, x + 3 and x + 5 is…….

#### Answer 8

#### Question 9

The mean of five numbers is 30. If one number is excluded, their mean …..

The excluded number is……

#### Answer 9

#### Question 10

If the mean of x1, x, is 7.5, and the mean of x1, X2, x3 is………….

#### Answer 10

#### Question 11

If each observation of the data is increased by 5, then their mean…………

#### Answer 11

#### Question 12

The mean of 100 observations is 50. If one of the observation which was 50 is replaced

by 150, the resulting mean will be

(a) 50-5

(b) 51

(c) 51-5

(d) 52

#### Answer 12

#### Question 13

For drawing a frequency polygon of a continuous frequency distribution, we plot the

points whose ordinates are the frequencies of the respective classes and abscissae are

respectively:

(a) upper limits of the classes

(c) class marks of the classes

(b) lower limits of the classes

(d) upper limits of preceding classes

#### Answer 13

#### Question 14

Median of the numbers 4, 4, 5, 7, 6, 7, 7, 3, 12 is

#### Answer 14

#### Question 15

The median of the data…………

#### Answer 15

#### Question 16

In a data, 10 numbers are arranged in ascending order. If the 8th entry is increased by

…………..

#### Answer 16

**Chapter-Test Statistics Class-9 Understanding Maths ML Aggarwal Solutions Chapter-20**

#### Question 1

Find the ………….

8, 8 5, 3, 2 9………..

#### Answer 1

#### Question 2

Find …………..of 48.

#### Answer 2

#### Question 3

The mean weight………students

#### Answer 3

#### Question 4

The mean…………….age

#### Answer 4

#### Question 5

If The mean……………observations

#### Answer 5

#### Question 6

The mean height………height

#### Answer 6

#### Question 7

The mean…………..mean.

#### Answer 7

#### Question 8

The following…………..91

#### Answer 8

#### Question 9

Draw……………marks

#### Answer 9

#### Question 10

In…………………under.

#### Answer 10

#### Question 11 Statistics ML Aggarwal Class-9 ICSE

Construct…………….distribution.

#### Answer 11

#### Question 12

The ………………polygonthe

#### Answer 12

#### Question 13

The …………………data.

#### Answer 13

#### Question 14

The…………distribution.

#### Answer 14

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