Finding the Third Proportional to 129,409.50 and 279,231

Step by Step Solution

1. Step 1: Write the proportion equation
   129,409.50 : 279,231 = 279,231 : x
2. Step 2: Convert to fraction form
   129,409.50/279,231 = 279,231/x
3. Step 3: Cross multiply
   129,409.50x = 279,231 × 279,231
4. Step 4: Simplify right side
   129,409.50x = 77,969,951,361
5. Step 5: Solve for x
   x = 77,969,951,361/129,409.50
6. Step 6: Final answer
   x = 602,505.62