Finding the Fourth Proportional to 12,619.72, 18,928.86 and 3,385

Step by Step Solution

1. Step 1: Write the proportion equation
   12,619.72 : 18,928.86 = 3,385 : x
2. Step 2: Convert to fraction form
   12,619.72/18,928.86 = 3,385/x
3. Step 3: Cross multiply
   12,619.72x = 18,928.86 × 3,385
4. Step 4: Simplify right side
   12,619.72x = 64,074,191.10
5. Step 5: Solve for x
   x = 64,074,191.10/12,619.72
6. Step 6: Final answer
   x = 5,077.31