Question

Craig earns extra money as a lifeguard he earns $37 for 4 hours and $64.75 for 7 hours. Explain how you know whether the relationship between earnings and time is a proportional relationship.

Answer 1

The ratio for earning of $37 for 4 hours is,

`(37)/(4)`

The ratio for earning of $64.75 for 7 hours is,

`(64.75)/(7)`

The relation between earning and time is proportional if both ratios are equal to each other.

Multiply the ratios such that denominator is same for both the cases.

`(37)/(4)\cdot(7)/(7)=(259)/(28)`

and

`(64.75)/(7)\cdot(4)/(4)=(259)/(28)`

So both ratios are equal to each other. Hence relation between time and earning is proportonal relationship.