Finding the Third Proportional to 90,640 and 198,404

Step by Step Solution

1. Step 1: Write the proportion equation
   90,640 : 198,404 = 198,404 : x
2. Step 2: Convert to fraction form
   90,640/198,404 = 198,404/x
3. Step 3: Cross multiply
   90,640x = 198,404 × 198,404
4. Step 4: Simplify right side
   90,640x = 39,364,147,216
5. Step 5: Solve for x
   x = 39,364,147,216/90,640
6. Step 6: Final answer
   x = 434,291.12