<h3>The cost of purchasing baby chicks at $4.50 per chick represents proportional relationship</h3>
<em><u>Solution:</u></em>
in a proportional relationship, one variable is always a constant value times the other.
y = kx
Where, k is a constant
<em><u>Option 1</u></em>
The cost of purchasing hay for $26 a bale with a delivery charge of $30
Cost = $ 26 a bale + 30
This does not forms a proportional relationship
<em><u>Option 2</u></em>
The cost of purchasing baby chicks at $4.50 per chick
Let "x" be the number of chicks
Therefore,

Thus, this forms a proportional relationship
<em><u>Option 3</u></em>
The cost of purchasing fencing at $29 a linear foot with an installation fee of $300
cost = $ 29 a linear foot + 300
This does not forms a proportional relationship
<em><u>Option 4</u></em>
The cost of renting a backhoe for $79 per hour with a non-refundable deposit of $300
cost = $ 79 per hour + 300
This does not forms a proportional relationship