6. A sample of 100 persons is to be taken from 128 nurses, 75 engineers, 97 doctors and 200 teachers. What is the size of the population?
a. 500
b. 450
c. 400
d. 350

7. A graphic device which is constructed by dividing a circle into sectors having a size proportional to the percentage it represents.
a. Maps
b. Pie Chart
c. Pictograph
d. Line Graph​