Finding the Third Proportional to 517,120 and 800,256

Step by Step Solution

1. Step 1: Write the proportion equation
   517,120 : 800,256 = 800,256 : x
2. Step 2: Convert to fraction form
   517,120/800,256 = 800,256/x
3. Step 3: Cross multiply
   517,120x = 800,256 × 800,256
4. Step 4: Simplify right side
   517,120x = 640,409,665,536
5. Step 5: Solve for x
   x = 640,409,665,536/517,120
6. Step 6: Final answer
   x = 1,238,415.97