Finding the Third Proportional to 128,760 and 278,956.50

Step by Step Solution

1. Step 1: Write the proportion equation
   128,760 : 278,956.50 = 278,956.50 : x
2. Step 2: Convert to fraction form
   128,760/278,956.50 = 278,956.50/x
3. Step 3: Cross multiply
   128,760x = 278,956.50 × 278,956.50
4. Step 4: Simplify right side
   128,760x = 77,816,728,892.25
5. Step 5: Solve for x
   x = 77,816,728,892.25/128,760
6. Step 6: Final answer
   x = 604,354.84