Question

A 4 pound bag of oranges costs $3.92.A 40 pound case of oranges costs $39.20.Which equation below is correct for this proportional relationship for pounds (x) and cost (y)

Answer 1

`y = 0.98x`

Explanation:

Given

Cost of 4 lb orange = $3.92

Cost of 40 lb orange = $39.20

Required

Determine the proportion

The proportion can be calculated susing:

`y = kx`

Where k = proportion

Make k the subject:

`k = (y)/(x)`

When y = 3.92 and x = 4

The proportion (k) is calculated as thus:

`k = (y)/(x)`

`k = (3.92)/(4)`

`k = 0.98`

When y = 39.2 and x = 40

Using the same formula:

`k = (39.2)/(40)`

`k = 0.98`

Substitute 0.98 for k in
`y = kx`

Hence, the proportional relationship is

`y = 0.98x`