Finding the Fourth Proportional to 1,116.17, 1,540.19 and 618.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,116.17 : 1,540.19 = 618.69 : x
2. Step 2: Convert to fraction form
   1,116.17/1,540.19 = 618.69/x
3. Step 3: Cross multiply
   1,116.17x = 1,540.19 × 618.69
4. Step 4: Simplify right side
   1,116.17x = 952,900.15
5. Step 5: Solve for x
   x = 952,900.15/1,116.17
6. Step 6: Final answer
   x = 853.72