Finding the Third Proportional to 309,922.50 and 678,813

Step by Step Solution

1. Step 1: Write the proportion equation
   309,922.50 : 678,813 = 678,813 : x
2. Step 2: Convert to fraction form
   309,922.50/678,813 = 678,813/x
3. Step 3: Cross multiply
   309,922.50x = 678,813 × 678,813
4. Step 4: Simplify right side
   309,922.50x = 460,787,088,969
5. Step 5: Solve for x
   x = 460,787,088,969/309,922.50
6. Step 6: Final answer
   x = 1,486,781.66