Finding the Third Proportional to 315,855 and 690,757.50

Step by Step Solution

1. Step 1: Write the proportion equation
   315,855 : 690,757.50 = 690,757.50 : x
2. Step 2: Convert to fraction form
   315,855/690,757.50 = 690,757.50/x
3. Step 3: Cross multiply
   315,855x = 690,757.50 × 690,757.50
4. Step 4: Simplify right side
   315,855x = 477,145,923,806.25
5. Step 5: Solve for x
   x = 477,145,923,806.25/315,855
6. Step 6: Final answer
   x = 1,510,648.63