Finding the Third Proportional to 328.78 and 504.56

Step by Step Solution

1. Step 1: Write the proportion equation
   328.78 : 504.56 = 504.56 : x
2. Step 2: Convert to fraction form
   328.78/504.56 = 504.56/x
3. Step 3: Cross multiply
   328.78x = 504.56 × 504.56
4. Step 4: Simplify right side
   328.78x = 254,583.32
5. Step 5: Solve for x
   x = 254,583.32/328.78
6. Step 6: Final answer
   x = 774.32