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Start with the compound interest formula where A is the return, P is the principal (the amount invested), r is the interest rate, n is the compound frequency, and t is the time (in years)

Plug in

,

,

, and

Multiply

Reduce

Divide both sides by 200.

Divide.

Take the 5th root of both sides.

Take the 5th root of 1.75 to get 1.118 (this is approximate)

Subtract 1 from both sides.

Combine like terms.
So the answer is

which is roughly 11.84%
So the interest rate needed is about 11.84%