Finding the Third Proportional to 143,490 and 312,815.25

Step by Step Solution

1. Step 1: Write the proportion equation
   143,490 : 312,815.25 = 312,815.25 : x
2. Step 2: Convert to fraction form
   143,490/312,815.25 = 312,815.25/x
3. Step 3: Cross multiply
   143,490x = 312,815.25 × 312,815.25
4. Step 4: Simplify right side
   143,490x = 97,853,380,632.56
5. Step 5: Solve for x
   x = 97,853,380,632.56/143,490
6. Step 6: Final answer
   x = 681,952.61