Finding the Third Proportional to 128,803.50 and 279,784.50

Step by Step Solution

1. Step 1: Write the proportion equation
   128,803.50 : 279,784.50 = 279,784.50 : x
2. Step 2: Convert to fraction form
   128,803.50/279,784.50 = 279,784.50/x
3. Step 3: Cross multiply
   128,803.50x = 279,784.50 × 279,784.50
4. Step 4: Simplify right side
   128,803.50x = 78,279,366,440.25
5. Step 5: Solve for x
   x = 78,279,366,440.25/128,803.50
6. Step 6: Final answer
   x = 607,742.54