Finding the Third Proportional to 87,128 and 188,656

Step by Step Solution

1. Step 1: Write the proportion equation
   87,128 : 188,656 = 188,656 : x
2. Step 2: Convert to fraction form
   87,128/188,656 = 188,656/x
3. Step 3: Cross multiply
   87,128x = 188,656 × 188,656
4. Step 4: Simplify right side
   87,128x = 35,591,086,336
5. Step 5: Solve for x
   x = 35,591,086,336/87,128
6. Step 6: Final answer
   x = 408,491.95