Finding the Third Proportional to 117.42 and 256.57

Step by Step Solution

1. Step 1: Write the proportion equation
   117.42 : 256.57 = 256.57 : x
2. Step 2: Convert to fraction form
   117.42/256.57 = 256.57/x
3. Step 3: Cross multiply
   117.42x = 256.57 × 256.57
4. Step 4: Simplify right side
   117.42x = 65,828.33
5. Step 5: Solve for x
   x = 65,828.33/117.42
6. Step 6: Final answer
   x = 560.61