Finding the Third Proportional to 318.89 and 492.56

Step by Step Solution

1. Step 1: Write the proportion equation
   318.89 : 492.56 = 492.56 : x
2. Step 2: Convert to fraction form
   318.89/492.56 = 492.56/x
3. Step 3: Cross multiply
   318.89x = 492.56 × 492.56
4. Step 4: Simplify right side
   318.89x = 242,610.96
5. Step 5: Solve for x
   x = 242,610.96/318.89
6. Step 6: Final answer
   x = 760.79