Exercise 19 B
Question 1
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 |
| Size | 0-10 | 10-20 | 20-30 | 30-40 | 40-50 | 50-60 |
| Frequency | 5 | 10 | 20 | 25 | 20 | 10 |
3.
| Class Interval | 0-5 | 5-10 | 10-15 | 15-20 | 20-25 |
| Frequency | 10 | 25 | 9 | 20 | 5 |
4.
| Marks | 0-10 | 10-20 | 20-30 | 30-40 | 40-50 |
| No. of students | 5 | 9 | 14 | 7 | 5 |
5. Complete: In the histogram below-people were surveyed, and-of them own between 20 and 60 books.
6. Complete: In the histogram shown below-students received grades between 70 and 100 , and students in all took the test.
<fig>
7. For the histogram shown alongside :
(a) What is the total number of students over whom our study has been conducted?
(b) Which time interval has the maximum number of students studying?
(c) Which time interval has the minimum number of students studying ?
(d) How many times is the number of students in the time interval $3 \mathrm{hrs}-6 \mathrm{hrs}$ greater than the number of students in the time interval $9 \mathrm{hrs}-12 \mathrm{hrs}$ ?
<fig>
8. For the histogram given alongside answer the questions that follow :
(a) What is the total number of girls in the class?
(b) Which group contains the maximum number of girls?
(c) Which groups have the minimum number of girls and how many?
(d) How many girls have a height of $145 \mathrm{~cm}$ or more?
<fig>
