Jagran Josh
Exercise 13.1 Class 10 Maths NCERT Solutions: Chapter 13 of the NCERT Class 10 Math textbook is Statistics, which deals with various concepts that students may have heard of for the first time. This is one of those topics in math that helps students throughout their lives, as it involves all the research fields needed to do big data analysis. Calculating probability, mean, mode, etc. are integral parts that students learn from this chapter.
Here, we have provided the NCERT Solutions for Class 10 Statistics, specifically, NCERT Solutions for Class 10 Maths Exercise 13.1. The questions in this exercise are primarily designed to help students become proficient in solving questions related to the mean of grouped data. Check out and download the complete NCERT solutions for Class 10 maths exercise 13.1 PDF from here.
NCERT Solutions for Class 10 Maths Exercise 13.1
Below are the NCERT solutions for Exercise 13.1. The complete PDF is attached at the end of this article.
Question 1: A survey was conducted by a group of students as a part of their environment awareness programme, in which they collected the following data regarding the number of plants in 20 houses in a locality. Find the mean number of plants per house.
|
Number of plants |
0 − 2 |
2 − 4 |
4 − 6 |
6 − 8 |
8 − 10 |
10 − 12 |
12 − 14 |
|
Number of houses |
1 |
2 |
1 |
5 |
6 |
2 |
3 |
Which method did you use for finding the mean, and why?
Solution:
To find the class mark (xi) for each interval, the following relation is used. Class mark (xi) = Upper class limit + lower class limit/2
Now,
|
Number of plants |
Number of houses (fi) |
xi |
fixi |
|
0 − 2 |
1 |
1 |
1 × 1 = 1 |
|
2 − 4 |
2 |
3 |
2 × 3 = 6 |
|
4 − 6 |
1 |
5 |
1 × 5 = 5 |
|
6 − 8 |
5 |
7 |
5 × 7 = 35 |
|
8 − 10 |
6 |
9 |
6 × 9 = 54 |
|
10 − 12 |
2 |
11 |
2 ×11 = 22 |
|
12 − 14 |
3 |
13 |
3 × 13 = 39 |
|
Total |
20 |
|
162 |
å fi = 20
å fi xi = 162
Mean, x = å fi xi/ å fi
x = 162/120
x = 8.1
Therefore, mean number of plants per house is 8.1.
Here, direct method has been used as the values of class marks (xi) and fi are small.
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The solution above might be confusing. To get a better view of this solution click on the link below to download the NCERT Ex 13.1 solution PDF.
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