Finding the Fourth Proportional to 1,017.55, 1,403.76 and 624.43

Step by Step Solution

1. Step 1: Write the proportion equation
   1,017.55 : 1,403.76 = 624.43 : x
2. Step 2: Convert to fraction form
   1,017.55/1,403.76 = 624.43/x
3. Step 3: Cross multiply
   1,017.55x = 1,403.76 × 624.43
4. Step 4: Simplify right side
   1,017.55x = 876,549.86
5. Step 5: Solve for x
   x = 876,549.86/1,017.55
6. Step 6: Final answer
   x = 861.43