Finding the Fourth Proportional to 1,142.57, 1,576.74 and 618.59

Step by Step Solution

1. Step 1: Write the proportion equation
   1,142.57 : 1,576.74 = 618.59 : x
2. Step 2: Convert to fraction form
   1,142.57/1,576.74 = 618.59/x
3. Step 3: Cross multiply
   1,142.57x = 1,576.74 × 618.59
4. Step 4: Simplify right side
   1,142.57x = 975,355.60
5. Step 5: Solve for x
   x = 975,355.60/1,142.57
6. Step 6: Final answer
   x = 853.65