The fire insurance premium on factories is £10 per square metre of floor space if that space is 500 m2 or less, but £15 per m2 for all larger areas.
(a) Prepare a worksheet that can calculate the total insurance due when the floor space of the factory is entered.
(b) Prepare a suitably labelled and titled graph showing how the total insurance due varies with the floor space of the factory for any range of floor spaces that are entered.