Mary plans to save $1000 each summer to buy a used car at the end of the fourth summer. At the end of each summer, she will deposit
the $1000 she earned from her summer job into her bank account. The table
shows the value of her deposits over the four year period. In the table, gis the
growth factor 1 + r where r is the annual interest rate expressed as a decimal.
End of End of End of End of
1st summer 2nd summer 3rd summer 4th summer
Value of 1st deposit 1000 1000g 1000g2 1000g3
Value of 2nd deposit ___ 1000 ? ?
Value of 3rd deposit ___ ___ 1000 ?
Value of 4th deposit ___ ___ ___ 1000
a. Copy and complete the table.
b. Write a polynomial function of gthat represents the value of Mary’s account
at the end of the fourth summer.
c. Writing Suppose Mary wants to buy a car that costs about $4300. What
growth factor does she need to obtain this amount? What annual interest rate
does she need? Explain how you found your answers.