Finding the Third Proportional to 686,280 and 990,049.50

Step by Step Solution

1. Step 1: Write the proportion equation
   686,280 : 990,049.50 = 990,049.50 : x
2. Step 2: Convert to fraction form
   686,280/990,049.50 = 990,049.50/x
3. Step 3: Cross multiply
   686,280x = 990,049.50 × 990,049.50
4. Step 4: Simplify right side
   686,280x = 980,198,012,450.25
5. Step 5: Solve for x
   x = 980,198,012,450.25/686,280
6. Step 6: Final answer
   x = 1,428,277.11