Finding the Fourth Proportional to 12,612.87, 17,279.72 and 12,139.93

Step by Step Solution

1. Step 1: Write the proportion equation
   12,612.87 : 17,279.72 = 12,139.93 : x
2. Step 2: Convert to fraction form
   12,612.87/17,279.72 = 12,139.93/x
3. Step 3: Cross multiply
   12,612.87x = 17,279.72 × 12,139.93
4. Step 4: Simplify right side
   12,612.87x = 209,774,487.32
5. Step 5: Solve for x
   x = 209,774,487.32/12,612.87
6. Step 6: Final answer
   x = 16,631.78