Answer
Find out the what is the effective cost per year of the extended warranty .
To proof
As given
The extended warranty on a $960 dishwasher is 21% of the purchase price and lasts for eight years.
21% is written in the decimal form
= 0.21
effective cost for the extended warranty = 0.21 × 960
= $ 201.6
= $25.2
Therefore the
effective cost per year of the extended warranty be $25.2
Option (d) is correct .
Hence proved