Finding the Third Proportional to 131,640 and 288,912

Step by Step Solution

1. Step 1: Write the proportion equation
   131,640 : 288,912 = 288,912 : x
2. Step 2: Convert to fraction form
   131,640/288,912 = 288,912/x
3. Step 3: Cross multiply
   131,640x = 288,912 × 288,912
4. Step 4: Simplify right side
   131,640x = 83,470,143,744
5. Step 5: Solve for x
   x = 83,470,143,744/131,640
6. Step 6: Final answer
   x = 634,078.88