Daisy went to an electronics store and paid $78.99 per gps navigator for five gps navigators and a flat rate fee for installation for a total of $428.45. rebecca went to another electronics store and paid $85.49 per gps navigator for five gps navigators plus a per gps navigator installation fee for a total of $464.35. what is the difference in the amounts they paid in installation charges? a. $3.40 b. $4.40 c. $2.40 d. $5.40