Finding the Third Proportional to 117,720 and 256,456

Step by Step Solution

1. Step 1: Write the proportion equation
   117,720 : 256,456 = 256,456 : x
2. Step 2: Convert to fraction form
   117,720/256,456 = 256,456/x
3. Step 3: Cross multiply
   117,720x = 256,456 × 256,456
4. Step 4: Simplify right side
   117,720x = 65,769,679,936
5. Step 5: Solve for x
   x = 65,769,679,936/117,720
6. Step 6: Final answer
   x = 558,695.89