Finding the Fourth Proportional to 1,116.05, 1,540.09 and 618.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,116.05 : 1,540.09 = 618.69 : x
2. Step 2: Convert to fraction form
   1,116.05/1,540.09 = 618.69/x
3. Step 3: Cross multiply
   1,116.05x = 1,540.09 × 618.69
4. Step 4: Simplify right side
   1,116.05x = 952,834.43
5. Step 5: Solve for x
   x = 952,834.43/1,116.05
6. Step 6: Final answer
   x = 853.75