Finding the Fourth Proportional to 12,663.72, 18,994.86 and 3,429

Step by Step Solution

1. Step 1: Write the proportion equation
   12,663.72 : 18,994.86 = 3,429 : x
2. Step 2: Convert to fraction form
   12,663.72/18,994.86 = 3,429/x
3. Step 3: Cross multiply
   12,663.72x = 18,994.86 × 3,429
4. Step 4: Simplify right side
   12,663.72x = 65,133,374.94
5. Step 5: Solve for x
   x = 65,133,374.94/12,663.72
6. Step 6: Final answer
   x = 5,143.31