Gavin wrote the equation $p=\frac{3(s+100)}{4}$ to represent $p$, the profit he makes from $s$ sales in his lawn-mowing business. Which equation is solved for $s$ ? $s=\frac{p-100}{3}$ $s=\frac{4 p-300}{3}$ $s=\frac{4 p}{300}$ $s=\frac{400 p}{3}$

Step 1 ：Given the equation: $p = \frac{3(s+100)}{4}$

Step 2 ：Solve for $s$ by multiplying both sides by 4: $4p = 3(s+100)$

Step 3 ：Distribute the 3: $4p = 3s + 300$

Step 4 ：Subtract 300 from both sides: $4p - 300 = 3s$

Step 5 ：Divide both sides by 3: $s = \frac{4p - 300}{3}$

Step 6 ：\boxed{s = \frac{4p - 300}{3}}$