Finding the Fourth Proportional to 1,139.01, 1,706.87 and 618.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.01 : 1,706.87 = 618.57 : x
2. Step 2: Convert to fraction form
   1,139.01/1,706.87 = 618.57/x
3. Step 3: Cross multiply
   1,139.01x = 1,706.87 × 618.57
4. Step 4: Simplify right side
   1,139.01x = 1,055,815.48
5. Step 5: Solve for x
   x = 1,055,815.48/1,139.01
6. Step 6: Final answer
   x = 926.96