Finding the Third Proportional to 117.28 and 255.80

Step by Step Solution

1. Step 1: Write the proportion equation
   117.28 : 255.80 = 255.80 : x
2. Step 2: Convert to fraction form
   117.28/255.80 = 255.80/x
3. Step 3: Cross multiply
   117.28x = 255.80 × 255.80
4. Step 4: Simplify right side
   117.28x = 65,432.04
5. Step 5: Solve for x
   x = 65,432.04/117.28
6. Step 6: Final answer
   x = 557.91