Finding the Third Proportional to 400.78 and 612.56

Step by Step Solution

1. Step 1: Write the proportion equation
   400.78 : 612.56 = 612.56 : x
2. Step 2: Convert to fraction form
   400.78/612.56 = 612.56/x
3. Step 3: Cross multiply
   400.78x = 612.56 × 612.56
4. Step 4: Simplify right side
   400.78x = 375,232.82
5. Step 5: Solve for x
   x = 375,232.82/400.78
6. Step 6: Final answer
   x = 936.25