Total amount of liquid soap prepared by the students for a craft fair = 84.5 ounces
Weight of each bottle in which students poured the soap = 6.5 ounces
Let us first calculate the number of bottles, each contains 6.5 ounces of soap from 84.5 ounces of soap.
So, Number of bottles =

= 13
So, 13 bottles are prepared which contains 6.5 ounces of soap from 84.5 ounces of soap.
The amount at which each bottle is sold = $5.50
The total amount earned by selling all the bottles of liquid soap =

= $71.5
So, the students will earn $71.5 if they sell all the bottles of liquid soap.