Finding the Third Proportional to 424.78 and 634.78

Step by Step Solution

1. Step 1: Write the proportion equation
   424.78 : 634.78 = 634.78 : x
2. Step 2: Convert to fraction form
   424.78/634.78 = 634.78/x
3. Step 3: Cross multiply
   424.78x = 634.78 × 634.78
4. Step 4: Simplify right side
   424.78x = 402,947.24
5. Step 5: Solve for x
   x = 402,947.24/424.78
6. Step 6: Final answer
   x = 948.60