Finding the Third Proportional to 86,616.56 and 128,659.50

Step by Step Solution

1. Step 1: Write the proportion equation
   86,616.56 : 128,659.50 = 128,659.50 : x
2. Step 2: Convert to fraction form
   86,616.56/128,659.50 = 128,659.50/x
3. Step 3: Cross multiply
   86,616.56x = 128,659.50 × 128,659.50
4. Step 4: Simplify right side
   86,616.56x = 16,553,266,940.25
5. Step 5: Solve for x
   x = 16,553,266,940.25/86,616.56
6. Step 6: Final answer
   x = 191,109.72