Finding the Fourth Proportional to 1,118.59, 1,543.79 and 621.28

Step by Step Solution

1. Step 1: Write the proportion equation
   1,118.59 : 1,543.79 = 621.28 : x
2. Step 2: Convert to fraction form
   1,118.59/1,543.79 = 621.28/x
3. Step 3: Cross multiply
   1,118.59x = 1,543.79 × 621.28
4. Step 4: Simplify right side
   1,118.59x = 959,118.89
5. Step 5: Solve for x
   x = 959,118.89/1,118.59
6. Step 6: Final answer
   x = 857.44