Finding the Third Proportional to 315,338.50 and 689,361

Step by Step Solution

1. Step 1: Write the proportion equation
   315,338.50 : 689,361 = 689,361 : x
2. Step 2: Convert to fraction form
   315,338.50/689,361 = 689,361/x
3. Step 3: Cross multiply
   315,338.50x = 689,361 × 689,361
4. Step 4: Simplify right side
   315,338.50x = 475,218,588,321
5. Step 5: Solve for x
   x = 475,218,588,321/315,338.50
6. Step 6: Final answer
   x = 1,507,011.00