Students can Download Class 10 Maths Chapter 13 Statistics Ex 13.1 Questions and Answers, Notes Pdf, KSEEB Solutions for Class 10 Maths helps you to revise the complete Karnataka State Board Syllabus and to clear all their doubts, score well in final exams.

## Karnataka State Syllabus Class 10 Maths Chapter 13 Statistics Ex 13.1

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.

Which method did you use for finding mean and why?

Answer:

Mean number of plants per house is 8.1. Direct method because X_{i} and f_{i} are small.

Question 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.

Answer:

By step deviation method.

assumed mean = a = 550,

Common factor = h = 20 [from class mark]

Mean daily wages of the workers in the factory is ₹ 145.20.

Question 3.

The following distribution shows the daily pocket allowance of children of a locality. The mean pocket allowance is ₹ 18. Find the missing frequency f.

Answer:

Mean = \(\overline{\mathbf{x}}\) = 18

18(f + 44) = 20f + 752

18f + 792 = 20f + 752

792 – 752 = 20f – 18f

2f = 40

f = \(\frac{40}{2}\)

Hence missing frequency is 20

Question 4.

Thirty women were examined in a hospital by a doctor and the number of heart beats per minute were recorded and summarised as follows. Find the mean heart beats per minute for these women, choosing a suitable method.

Answer:

Step deviation method.

Assumed mean = a = 75.5

Common factor = h = 1 [From class mark]

Mean of heart beats per minute is 75.9

Question 5.

In a retail market, fruit vendors were selling mangoes kept in packing boxes. These boxes contained varying number of mangoes. The following was the distribution of mangoes according to the number of boxes.

Find the mean number of mangoes kept in a packing box. Which method of finding the mean did you choose?

Answer:

Assumed mean = a = 57

Common factor = h = 3 [common factor from class mark ]

Mean number of mango’s kept in box is 57.19.

Question 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.

Answer:

assumed mean = a = 225

Common factor = h = 25 [from class mark]

Hence, the mean daily expenditure of food is ₹ 211

Question 7.

To find out the concentration of SO_{2} 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 SO_{2} in the air.

Answer:

assumed mean = a = 0.10

Common factor = h = 0.02 [class mark]

∴ The mean concentration of SO_{2} in the air is 0.099 ppm.

Question 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.

Answer:

Mean number of days student was absent is 12.47.

Question 9.

The following table gives the literacy rate (in percentage) of 35 cities. Find the mean literacy rate.

Answer:

Assume mean = a = 70

Class size = h = 10.

= 70 – 0.57 = 69.43

∴ Mean literacy rate is 69.43%