Loft insulation reduces annual heating costs by 20%. after he insulated his loft, curtleys annual heating cost was £520. work out curtleys annual heating cost would have been, if he had not insulated his loft.

$650

Step-by-step explanation:

Let x represent curtleys original annual heating cost.

We have been given that Loft insulation reduces annual heating costs by 20%.

So the cost after 20% reduction would be 80% of original cost that is .

We have been given that after he insulated his loft, curtleys annual heating cost was £520. We can represent this information in an equation as:

Therefore, Curtley's annual heat costing would have been $650, if he had not insulated his loft.

boxplot e is the answer