## Introduction to Data Interpretation

#### Data Interpretation

Direction: Study the histogram of marks (in Mathematics) distribution of 50 students of class IX and answer the following questions. 1. The average marks of the students are

1. On the basis of given graph in question , we have
Here , f1 = 10 , x1 = 7 , f2 = 30 , x2 = 8 , f3 = 50 , x3 = 18 , f4 = 70 , x4 = 4 , f5 = 90 , x5 = 13

 Mid-value of class-interval (x) = Highest value + Lowest value 2

 ∴ Average = Σ fx Σ f

where Σf = Total number of students
 Required average marks = 10 × 7 + 30 × 8 + 50 × 18 + 70 × 4 + 90 × 13 50

##### Correct Option: A

On the basis of given graph in question , we have
Here , f1 = 10 , x1 = 7 , f2 = 30 , x2 = 8 , f3 = 50 , x3 = 18 , f4 = 70 , x4 = 4 , f5 = 90 , x5 = 13

 Mid-value of class-interval (x) = Highest value + Lowest value 2

 ∴ Average = Σ fx Σ f

where Σf = Total number of students
 Required average marks = 10 × 7 + 30 × 8 + 50 × 18 + 70 × 4 + 90 × 13 50

 Required average marks = 70 + 240 + 900 + 280 + 1170 50

 Required average marks = 2660 = 53.2 50

1. The number of students who have secured marks less than 60 is :

1. From the given above histogram , we can see
The number of students who have scored interval 0-20 = 7
The number of students who have scored interval 0-20 = 8
The number of students who have scored interval 0-20 = 18

##### Correct Option: C

From the given above histogram , we can see
The number of students who have scored interval 0-20 = 7
The number of students who have scored interval 0-20 = 8
The number of students who have scored interval 0-20 = 18
Students who score less than 60 marks = 7 + 8 + 18 = 33

Direction: Study the following histogram of data related to literate people of different age groups and answer the questions given below. 1. The respective ratio of literate people in the age group of 20 to 35 years to that in the age group of 30 to 45 years is

1. According to given histogram , we have
Number of literate people in the age group of 20 to 35 years = 800 + 650 + 600 = 2050
Number of literate people in the age group of 30 to 45 years = 600 + 500 + 250 = 1350
Required ratio = Number of literate people in the age group of 20 to 35 years : Number of literate people in the age group of 30 to 45 years

##### Correct Option: C

According to given histogram , we have
Number of literate people in the age group of 20 to 35 years = 800 + 650 + 600 = 2050
Number of literate people in the age group of 30 to 45 years = 600 + 500 + 250 = 1350
Required ratio = Number of literate people in the age group of 20 to 35 years : Number of literate people in the age group of 30 to 45 years
∴ Required ratio = 2050 : 1350 = 41 : 27

1. The percentage of the literate people in the age group 30 to 45 years is

1. On the basis of given graph in question ,
Number of literate people in the age group 30–45 years = 600 + 500 + 250 = 1350
Total literate people = 3700 + 350 = 4050

 Required percent = 1350 × 100 4050

##### Correct Option: B

On the basis of given graph in question ,
Number of literate people in the age group 30–45 years = 600 + 500 + 250 = 1350
Total literate people = 3700 + 350 = 4050

 Required percent = 1350 × 100 4050

 Required percent = 100 = 33.33% 3

1. The number of literate people in the age group of 20 to 35 years is

1. According to given histogram , we have
Number of literate people in the age interval 20-25 = 800
Number of literate people in the age interval 25-30 = 650
Number of literate people in the age interval 30-35 = 600

##### Correct Option: A

According to given histogram , we have
Number of literate people in the age interval 20-25 = 800
Number of literate people in the age interval 25-30 = 650
Number of literate people in the age interval 30-35 = 600
Required answer = 800 + 650 + 600 = 2050