NCERT Solutions for Class 10 Maths Exercise 14.1 Chapter 14 Statistics- FREE PDF Download
NCERT Class 10 Maths Ch 14 is one of the most important ones in the NCERT syllabus. Duly following NCERT Solutions for Class 10 Maths
Chapter 14 ensures you that there will be no hindrance when you opt for more advanced branches of Maths. This is where CoolGyan comes in. Our free Class 10 Statistics solutions will help you understand the chapter thoroughly.
NCERT Solutions for Class 10 Maths Chapter 14 – Statistics
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.
Which method did you use for finding the mean and why?
Mean 
= 8.1
Hence mean number of plants per house is 8.1.
2. Consider the following distribution of daily wages of 50 workers of a factory.
Find the mean daily wages of the workers of the factory by using an appropriate method.
From given data, Assume mean 
= 150, Width of the class 
= 20
= 
Using formula, Mean 
= 
= 150 – 4.8 = 145.2
Hence mean daily wages of the workers of factory is Rs. 145.20.
3. The following distribution shows the daily pocket allowance of children of a locality. The mean pocket allowance is Rs.18. Find the missing frequency 
From given data, Assume mean = 18
Hence missing frequency is 20.
4. Thirty women were examined in a hospital by a doctor and the number of heart beats per minute were recorded and summarized as follows:
( in the class interval 77-80 , 78.4 changes to 78.5)
From given data, Assume mean = 75.5, Width of the class = 3
= 
(approx.)
Using formula, Mean = 75.5 + 3 (0.13) = 75.5 + 0.39 = 75.89
Hence mean heart beat per minute for women is 75.89.
5. In a retail market, fruit vendors were selling mangoes kept in packing boxes. These boxes contained varying number mangoes. The following was the distribution of mangoes according to the number of boxes.
{change the frequency in above table as: 50-52 (15) 53-55 (110) 56-58 (135) 59-61 (115) 62-64 (25)}
Find the mean number of mangoes kept in a packing box. Which method of finding the mean did you choose?
we convert the class interval firstly into exclusive form given as
| True Class Interval | No. of boxes (fi) | Class mark (xi) | ui=xi−ahui=xi−ah | fiui |
| 49.5-52.5 | 15 | 51 | -2 | -30 |
| 52.5-55.5 | 110 | 54 | -1 | -110 |
| 55.5-58.5 | 135 | 57 | 0 | 0 |
| 58.5-61.5 | 115 | 60 | 1 | 115 |
| 61.5-64.5 | 25 | 63 | 2 | 50 |
| ∑fi=400∑fi=400 | ∑fiui=25∑fiui=25 |
From given data, Assume mean = 57, Width of the class = 3
= 
(approx.)
Using formula, Mean = 57 + 3 (0.0625) = 57 + 0.1875 = 57.1875 = 57.19 (approx.)
Hence mean number of mangoes kept in a packing box is 57.19.
6. The table below shows the daily expenditure on food of 25 households in a locality:
Find the mean daily expenditure on food by a suitable method.
From given data, Assume mean = 225, Width of the class = 50
= 
Using formula, Mean = 225 + 50 (– 0.28) = 225 – 14 = 211
Hence mean daily expenditure on food is Rs. 211.
7. To find out the concentration of SO2 in the air (in parts per million, i.e., ppm), the data was collected for 30 localities in a certain city and is presented below:
Find the mean concentration of SO2 in the air.
From given data, Assume mean = 0.10, Width of the class = 0.04
= 
(approx.)
Using formula, Mean = 0.10 + 0.04 (– 0.033) = 0.10 – 0.0013 = 0.0987 (approx.)
Hence mean concentration of SO2 in air is 0.0987 ppm.
8. A class teacher has the following absentee record of 40 students of a class for the whole term. Find the mean number of days a student was absent.
From given data, Assume mean = 17
= 
= 12.48
Hence mean 12.48 number of days a student was absent.
9. The following table gives the literacy rate (in percentage) of 35 cities. Find the mean literacy rate.
From given data, Assume mean = 70, Width of the class = 10
= 
Using formula, Mean = 70 + 10 (– 0.057) = 70 – 0.57 = 69.43
Hence mean literacy rate is 69.43%.
