{"id":245814,"date":"2021-03-09T11:16:50","date_gmt":"2021-03-09T11:16:50","guid":{"rendered":"https:\/\/www.indcareer.com\/schools\/?p=245814"},"modified":"2023-09-20T07:48:09","modified_gmt":"2023-09-20T07:48:09","slug":"ncert-solutions-for-11th-class-maths-chapter-15-statistics","status":"publish","type":"post","link":"https:\/\/www.indcareer.com\/schools\/ncert-solutions-for-11th-class-maths-chapter-15-statistics\/","title":{"rendered":"NCERT Solutions for 11th Class Maths: Chapter 15-Statistics"},"content":{"rendered":"\n

Class 11: Maths Chapter 15 solutions. Complete Class 11 Maths Chapter 15 Notes.<\/p>\n\n\n\n

NCERT Solutions for 11th Class Maths: Chapter 15-Statistics<\/strong><\/h2>\n\n\n\n

NCERT 11th Maths Chapter 15, class 11 Maths Chapter 15 solutions<\/p>\n\n\n\n

Exercise 15.1<\/strong><\/h4>\n\n\n\n

Find the mean deviation about the mean for the data in Exercises 1 and 2.<\/strong><\/p>\n\n\n\n

Question 1.<\/strong>
4, 7, 8, 9, 10, 12, 13, 17<\/p>\n\n\n\n


Solution:<\/strong>
Mean of the given data is
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n

Question 2.<\/strong>
38, 70, 48, 40, 42, 55, 63, 46, 54, 44<\/p>\n\n\n\n


Solution:<\/strong>
Mean of the given data is
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n
\"NCERT<\/figure>\n\n\n\n

 Question 3.<\/strong>
13, 17, 16, 14, 11, 13, 10, 16, 11, 18, 12, 17<\/p>\n\n\n\n


Solution:<\/strong>
Arranging the data in ascending order, we have
10, 11, 11, 12, 13, 13, 14, 16, 16, 17, 17, 18
Here n = 12 (which is even)
So median is the average of 6th and 7th observations
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n

Question 4.<\/strong>
36, 72, 46, 42, 60, 45, 53, 46, 51, 49<\/p>\n\n\n\n


Solution:<\/strong>
Arranging the data in ascending order, we have 36, 42, 45, 46, 46, 49, 51, 53, 60, 72
Here n = 10 (which is even)
So median is the average of 5th and 6th observations
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n

Find the mean deviation about the mean for the data in Exercises 5 and 6.<\/strong><\/p>\n\n\n\n

Question 5.<\/strong>
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n


Solution:<\/strong>
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n

Question 6.<\/strong>
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n


Solution:<\/strong>
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n

Find the mean deviation about the median for the data in Exercises 7 and 8.<\/strong><\/p>\n\n\n\n

 Question 7.<\/strong>
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n


Solution:<\/strong>
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n

Question 8.<\/strong>
<\/p>\n\n\n\n

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Solution:<\/strong>
<\/p>\n\n\n\n

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Find the mean deviation about the mean for the data in Exercises 9 and 10.<\/strong><\/p>\n\n\n\n

 Question 9.<\/strong>
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n


Solution:<\/strong>
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n

Question 10.<\/strong>
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n


Solution:<\/strong>
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n
\"NCERT<\/figure>\n\n\n\n

Question 11.<\/strong>
Find the mean deviation about median for the following data:
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n


Solution:<\/strong>
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n

Question 12.<\/strong>
Calculate the mean deviation about median age for the age distribution of 100 persons given below:
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n

<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n



[Hint: Convert the given data into continuous frequency distribution by subtracting 0.5 from lower limit and adding 0.5 to the upper limit of each class interval]<\/p>\n\n\n\n


Solution:<\/strong>
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n
Exercise 15.2<\/strong><\/h5>\n\n\n\n

NCERT 11th Maths Chapter 15<\/p>\n\n\n\n

Find the mean and variance for each of the data in Exercises 1 to 5.<\/strong><\/p>\n\n\n\n

Question 1.<\/strong>
6, 7, 10, 12, 13, 4, 8, 12<\/p>\n\n\n\n


Solution:<\/strong>
Here xi<\/sub> = 6, 7, 10, 12, 13, 4, 8, 12
\u2234 \u03a3xi<\/sub> = 6 + 7 + 10 + 12 + 13 + 4 + 8 + 12 = 72
n = 8
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n
\"NCERT<\/figure>\n\n\n\n

Question 2.<\/strong>
First n natural numbers<\/p>\n\n\n\n


Solution:<\/strong>
Here xi<\/sub> = 1, 2, 3, 4, \u2026\u2026\u2026.n
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n

NCERT 11th Maths Chapter 15<\/p>\n\n\n\n

Question 3.<\/strong>
First 10 multiples of 3<\/p>\n\n\n\n


Solution:<\/strong>
Here xi<\/sub> = 3, 6, 9, 12, 15, 18, 21, 27, 30,
\u03a3xi<\/sub> = 3 + 6 + 9 + 12 + 15 + 18 + 21 + 24 + 27 + 30 = 165
n = 10
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n

Question 4.<\/strong>
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n


Solution:<\/strong>
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n

Question 5.<\/strong>
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n


Solution:<\/strong>
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n

 Question 6.<\/strong>
Find the mean and standard deviation using short-cut method
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n


Solution:<\/strong>
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n
\"NCERT<\/figure>\n\n\n\n

Find the mean and variance for the following frequency distributions in Exercises 7 and 8.<\/strong><\/p>\n\n\n\n

NCERT 11th Maths Chapter 15 <\/strong><\/p>\n\n\n\n

Question 7.<\/strong>
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n


Solution:<\/strong>
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n

 Question 8.<\/strong>
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n


Solution:<\/strong>
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n
\"NCERT<\/figure>\n\n\n\n

NCERT 11th Maths Chapter 15<\/p>\n\n\n\n

Question 9.<\/strong>
Find the mean, variance and standard deviation using short-cut method.
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n


Solution:<\/strong>
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n
\"NCERT<\/figure>\n\n\n\n

NCERT 11th Maths Chapter 15 <\/strong><\/p>\n\n\n\n

Question 10.<\/strong>
The diameters of circles (in mm) drawn in a design are given below:
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n


Calculate the standard deviation and mean diameter of the circles.
[Hint: First make the data continuous by making the classes as 32.5 \u2013 36.5, 36.5 \u2013 40.5, 40.5 \u2013 44.5, 44.5 \u2013 48.5, 48.5 \u2013 52.5 and then proceed.]<\/p>\n\n\n\n


Solution:<\/strong>
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n
Exercise 15.3<\/strong><\/h5>\n\n\n\n

Question 1.<\/strong>
From the data given below state which group is more variable, A or B?
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n


Solution:<\/strong>
For Group A :
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n
\"NCERT<\/figure>\n\n\n\n
\"NCERT<\/figure>\n\n\n\n

Question 2.<\/strong>
From the prices of shares X and Y below, find out which is more stable in value:
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n


Solution:<\/strong>
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n
\"NCERT<\/figure>\n\n\n\n

 Question 3.<\/strong>
An analysis of monthly wages paid to workers in two firms A and B, belonging to the same industry, gives the following results:
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n


(i)<\/strong> Which firm A or B pays larger amount as monthly wages?
(ii)<\/strong> Which firm, AorB, shows greater variability in individual wages?<\/p>\n\n\n\n


Solution:<\/strong>
(i) Firm A :<\/strong>
Number of wage earners (n1<\/sub>) = 586
Mean of monthly wages (x1\u00af\u00af\u00af\u00af\u00af) = Rs.5253
\u2234 Total monthly wages = 5253 x 586
= Rs. 3078258
Firm B :
Number of wage earners (n2<\/sub>) = 648
Mean of monthly wages (x2\u00af\u00af\u00af\u00af\u00af) = Rs.5253
\u2234 Total monthly wages = 5253 x 648
= Rs. 3403944
Hence, Firm B pays larger amount as monthly wages.<\/p>\n\n\n\n

(ii)<\/strong> Since both the firms have same mean of monthly wages, so the firm with greater variance will have more variability in individual wages. Thus firm B will have more variability in individual wages.<\/p>\n\n\n\n

Question 4.<\/strong>
The following is the record of goals scored by team A in a football session:
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n


For the team B, mean number of goals scored per match was 2 with a standard deviation 1.25 goals. Find which team may be considered more consistent?
Solution:<\/strong>
For team A:
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n

 Question 5.<\/strong>
The sum and sum of squares corresponding to length x (in cm) and weight y (in gm) of 50 plant products are given below:
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n


Which is more varying, the length or weight?<\/p>\n\n\n\n


Solution:<\/strong>
<\/p>\n\n\n\n

\"NCERT<\/figure>\n\n\n\n
\"NCERT<\/figure>\n\n\n\n

NCERT 11th Maths Chapter 15, class 11 Maths Chapter 15 solutions<\/p>\n\n\n\n

NCERT Solutions for 11th Class Maths: Chapter 15: Download PDF<\/strong><\/h2>\n\n\n\n

NCERT Solutions for 11th Class Maths: Chapter 15-Statistics<\/p>\n\n\n\n

Download PDF<\/strong>: NCERT Solutions for 11th Class Maths: Chapter 15-Statistics PDF<\/a><\/p>\n\n\n\n

Chapterwise NCERT Solutions for Class 1<\/strong>1 Maths :<\/h2>\n\n\n\n