Multiply the cost per yard by the number of yards bought.
Change 3 1/2 to an improper fraction:
3 1/2 = 7/2
Now you have 7/2 x 5/8
Multiply the top numbers together and then the bottom numbers together:
(7 x 5) / (2 x 8) = 35/16
Now rewrite the improper fraction as a proper fraction:
2 3/16 which would be $2.19