In her assignment, Pat is representing the populations of cities using circles. The area of each circle is directly proportional to the population of the city it represents.
(a) If a city of population 20 000 is represented by a circle of radius 1.5 cm, what would
be the radius of the circle representing:
(i) City A, population 10 000?
(ii) City B, population 36 500?
(b) Would Pat be able to use a circle to represent a city of population 4 500 000? Explain
your answer.