Finding the Third Proportional to 129,123 and 279,688.50

Step by Step Solution

1. Step 1: Write the proportion equation
   129,123 : 279,688.50 = 279,688.50 : x
2. Step 2: Convert to fraction form
   129,123/279,688.50 = 279,688.50/x
3. Step 3: Cross multiply
   129,123x = 279,688.50 × 279,688.50
4. Step 4: Simplify right side
   129,123x = 78,225,657,032.25
5. Step 5: Solve for x
   x = 78,225,657,032.25/129,123
6. Step 6: Final answer
   x = 605,822.80