Finding the Third Proportional to 425,749.50 and 638,685

Step by Step Solution

1. Step 1: Write the proportion equation
   425,749.50 : 638,685 = 638,685 : x
2. Step 2: Convert to fraction form
   425,749.50/638,685 = 638,685/x
3. Step 3: Cross multiply
   425,749.50x = 638,685 × 638,685
4. Step 4: Simplify right side
   425,749.50x = 407,918,529,225
5. Step 5: Solve for x
   x = 407,918,529,225/425,749.50
6. Step 6: Final answer
   x = 958,118.63