S.chand books class 8 maths solution chapter 29 Graphical Representation of Data exercise 29 B

 EXERCISE 29 B

Question 1

Represent the following distribution of ages (in years) of 35 teachers in a school by means of a histogram.

Age(in years)	25-30	30-35	35-40	40-45	45-50
Number of teachers	12	11	8	1	3

Sol :

Draw histrograms for the following frequency distributions.

Question 2

Size	0-10	10-20	20-30	30-40	40-50	50-60
Frequency	5	10	20	25	20	10

Sol :

Question 3

Class interval	0-5	5-10	10-15	15-20	20-25
Frequency	10	25	9	20	5

Sol :

Question 4

Marks	0-10	10-20	20-30	30-40	40-50
Number of students	5	9	14	7	5

Sol :

Question 5

For the histogram shown alogside.

(i) What is the total number of students over whom our study has been conducted ?

Sol : 56 students

(ii) Which time interval has the maximum number of students studying ?

Sol : (3 - 6) hours

(iii) Which time interval has the minimum number of students studying?

Sol : (12 - 15) hours

(iv) How many times is the number of students in the time interval 3hours - 6 hours greater than the number of students in the time interval 9 hours - 12 hours?

Sol : 5 times

Question 6

For the histogram given alongside answer the questions that follow.

(i) What is the total number of girls in the class?

Sol :  22

(ii) Which group contains the maximum number of girls?

Sol : (140 - 145)cm

(iii) Which groups have the minimum number of girls and how many ?

Sol : (125 - 130)cm ; (155 - 160)cm ; 1

(vi) How many girls have a height of 145 cm or more ?

Sol : 7 girls