Finding the Third Proportional to 489,564 and 689,431.50

Step by Step Solution

1. Step 1: Write the proportion equation
   489,564 : 689,431.50 = 689,431.50 : x
2. Step 2: Convert to fraction form
   489,564/689,431.50 = 689,431.50/x
3. Step 3: Cross multiply
   489,564x = 689,431.50 × 689,431.50
4. Step 4: Simplify right side
   489,564x = 475,315,793,192.25
5. Step 5: Solve for x
   x = 475,315,793,192.25/489,564
6. Step 6: Final answer
   x = 970,896.13