I have an algebra question

i need to do a project for my algebra class and i need to find the amount of money my parents needed to invest at my birth in order to save for college for me. the total amount of money for college is $166976 and i need to find for p ie the money they need to initially invest

this is the equation i must use, i am also not sure of the compounding,
166976=p(1+0.0663)^(18)

166976=p(1+0.0663)^(18)
solve term in the brackets
166976=p(1.0663)^18
the term in brackets to the 18th power
166976=p(3.175626)
divide both sides by the term in the brackets to isolate p
52580.4991 = p