Finding the Third Proportional to 489,442.50 and 689,256

Step by Step Solution

1. Step 1: Write the proportion equation
   489,442.50 : 689,256 = 689,256 : x
2. Step 2: Convert to fraction form
   489,442.50/689,256 = 689,256/x
3. Step 3: Cross multiply
   489,442.50x = 689,256 × 689,256
4. Step 4: Simplify right side
   489,442.50x = 475,073,833,536
5. Step 5: Solve for x
   x = 475,073,833,536/489,442.50
6. Step 6: Final answer
   x = 970,642.79