Answer:
$4.50
Step-by-step explanation:
Use the mean formula: mean = sum of elements / number of elements
Let x represent the cost of the fifth book, and solve for x:
mean = sum of elements / number of elements
3.25 = (11.75 + x) / 5
16.25 = 11.75 + x
4.5 = x
So, the cost of the fifth book was $4.50
