Question

Observe the figure 7.4 and answer the following questions.
Graphic

(i) What type of bar diagram is it?
(ii) How many boys and girls are there in division D?
(iii) How many girls are there in division B?
(iv) Which division has the equal number of boys and girls?
(v) Write the ratio of boys to girls in 'A' division.
(vi) What is the total strength of all divisions?
(vii) What is the average of girls of all divisions?

Answer 1

(i) Since there are two parts, i.e., shaded and unshaded, the diagram is a sub-divided bar diagram.

(ii) There are 50 girls in division D.
Number of boys in division D = 70$-$50 = 20

(iii) There are 30 girls in division B.

(iv) The division that has an equal number of boys and girls is division C.

(v) Number of girls in division A = 50
Number of boys in division D = 80$-$50 = 30
Ratio of boys to girls in division A = $\frac{30}{50}=\frac{3}{5}=3:5$
(vi) Total strength of all divisions = Sum of the heights of all bars
= 80 + 70 + 80 + 70 = 300

(vii) The average number of girls in all divisions can be calculated as:

$$\begin{gathered} \frac{\mathrm{Number}\mathrm{of}\mathrm{girls}\mathrm{in}\mathrm{all}\mathrm{divisions}}{\mathrm{Number}\mathrm{of}\mathrm{divisions}} \\ =\frac{50+30+40+50}{4} \\ =\frac{170}{4} \\ =42.5 \end{gathered}$$