Finding the Third Proportional to 117,216 and 256,488

Step by Step Solution

1. Step 1: Write the proportion equation
   117,216 : 256,488 = 256,488 : x
2. Step 2: Convert to fraction form
   117,216/256,488 = 256,488/x
3. Step 3: Cross multiply
   117,216x = 256,488 × 256,488
4. Step 4: Simplify right side
   117,216x = 65,786,094,144
5. Step 5: Solve for x
   x = 65,786,094,144/117,216
6. Step 6: Final answer
   x = 561,238.18