Finding the Fourth Proportional to 1,016.78, 1,403.88 and 624.32

Step by Step Solution

1. Step 1: Write the proportion equation
   1,016.78 : 1,403.88 = 624.32 : x
2. Step 2: Convert to fraction form
   1,016.78/1,403.88 = 624.32/x
3. Step 3: Cross multiply
   1,016.78x = 1,403.88 × 624.32
4. Step 4: Simplify right side
   1,016.78x = 876,470.36
5. Step 5: Solve for x
   x = 876,470.36/1,016.78
6. Step 6: Final answer
   x = 862.01