Finding the Third Proportional to 551,185.50 and 780,139.50

Step by Step Solution

1. Step 1: Write the proportion equation
   551,185.50 : 780,139.50 = 780,139.50 : x
2. Step 2: Convert to fraction form
   551,185.50/780,139.50 = 780,139.50/x
3. Step 3: Cross multiply
   551,185.50x = 780,139.50 × 780,139.50
4. Step 4: Simplify right side
   551,185.50x = 608,617,639,460.25
5. Step 5: Solve for x
   x = 608,617,639,460.25/551,185.50
6. Step 6: Final answer
   x = 1,104,197.48