Please help with word probem!

[Guest]

Sailboat Speed
The sail area-displacement ratio S provides a measure of the sail power available to drive a boat. For a boat with a displacement of d pounds and a sail area of A square feet.
S=16Ad^-2/3
A. Find s to the nearest tenth for the Tartan 4100, which has a sail area of 810 square feet and a displacement of 23,245 pounds.
B. Solve the formula for d.

This is what I have S=16(810)(23,245)^-2/3 for part A, but for part b what would I do?

 

[Gene]

If it were A=pi*R^2 could you solve for R? It is almost the same problem, just a diferent power.
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Gene

 

[Guest]

reply to word problem help

Would I then would it be like s/16A=d?

 

[Gene]

Nope, you lost the exponent.
A=pi*r^2
r=(A/pi)^(1/2)