Finding the Fourth Proportional to 1,118.18, 1,543.05 and 620.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,118.18 : 1,543.05 = 620.83 : x
2. Step 2: Convert to fraction form
   1,118.18/1,543.05 = 620.83/x
3. Step 3: Cross multiply
   1,118.18x = 1,543.05 × 620.83
4. Step 4: Simplify right side
   1,118.18x = 957,971.73
5. Step 5: Solve for x
   x = 957,971.73/1,118.18
6. Step 6: Final answer
   x = 856.72