Finding the Fourth Proportional to 1,038.18, 1,432.59 and 618.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,038.18 : 1,432.59 = 618.57 : x
2. Step 2: Convert to fraction form
   1,038.18/1,432.59 = 618.57/x
3. Step 3: Cross multiply
   1,038.18x = 1,432.59 × 618.57
4. Step 4: Simplify right side
   1,038.18x = 886,154.88
5. Step 5: Solve for x
   x = 886,154.88/1,038.18
6. Step 6: Final answer
   x = 853.56