Finding the Fourth Proportional to 1,139.94, 1,572.54 and 720.18

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.94 : 1,572.54 = 720.18 : x
2. Step 2: Convert to fraction form
   1,139.94/1,572.54 = 720.18/x
3. Step 3: Cross multiply
   1,139.94x = 1,572.54 × 720.18
4. Step 4: Simplify right side
   1,139.94x = 1,132,511.86
5. Step 5: Solve for x
   x = 1,132,511.86/1,139.94
6. Step 6: Final answer
   x = 993.48