Finding the Third Proportional to 128,809.50 and 279,798

Step by Step Solution

1. Step 1: Write the proportion equation
   128,809.50 : 279,798 = 279,798 : x
2. Step 2: Convert to fraction form
   128,809.50/279,798 = 279,798/x
3. Step 3: Cross multiply
   128,809.50x = 279,798 × 279,798
4. Step 4: Simplify right side
   128,809.50x = 78,286,920,804
5. Step 5: Solve for x
   x = 78,286,920,804/128,809.50
6. Step 6: Final answer
   x = 607,772.88