Finding the Third Proportional to 128,775 and 279,721.50

Step by Step Solution

1. Step 1: Write the proportion equation
   128,775 : 279,721.50 = 279,721.50 : x
2. Step 2: Convert to fraction form
   128,775/279,721.50 = 279,721.50/x
3. Step 3: Cross multiply
   128,775x = 279,721.50 × 279,721.50
4. Step 4: Simplify right side
   128,775x = 78,244,117,562.25
5. Step 5: Solve for x
   x = 78,244,117,562.25/128,775
6. Step 6: Final answer
   x = 607,603.32