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**1. Homework Statement**

At a rock concert, the engineer decides that the music isn't loud enough. He turns up the amplifiers so that the amplitude of the sound, where you're sitting, increases by 87.0%. By what percentage does the intensity increase? Do not enter unit.

**2. Homework Equations**

I used the fact that intensity is proportional to amplitude squared.

(A2/A1)^2 = I2/I1

**3. The Attempt at a Solution**

85% increase in A, so:

(1.85)^2=I2/I1

3.4225=I2/I1

I2=3.4225I1

3.4225x100= 342%

342%-100% = 242%

Answer=242 <-- which is incorrect.

where did I make my mistake?