Cost in dollars Books Delivered $27.25 4 $39.25 6 $75.25 12 $93.25 15 Mr. Peterson's Book Store delivers to customers after they have purchased. The costs are shown above in the table a. What is the cost per book? b. What is the delivery fee? Solve each proportion Help please

  a) cost per book: $6

  b) delivery fee: $3.25

Step-by-step explanation:

If we assume the cost per book and the delivery fee are constant, then we can find the cost of 2 books by subtracting the cost for 4 books from the cost for 6 books

  cost per book = (cost for 6 books - cost for 4 books)/(6 -4)

  = ($39.25 -27.25)/2 = $12/2 = $6 . . . . . cost per book

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The delivery charge will be the difference between the delivered cost and the cost of the books. For 4 books, that is ...

  delivery charge = $27.25 -4(6.00) = $3.25

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Additional comment

The relationship between delivered cost and number of books is not proportional. There are no proportions to solve in this problem.