Finding the Fourth Proportional to 1,118.58, 1,543.71 and 621.33

Step by Step Solution

1. Step 1: Write the proportion equation
   1,118.58 : 1,543.71 = 621.33 : x
2. Step 2: Convert to fraction form
   1,118.58/1,543.71 = 621.33/x
3. Step 3: Cross multiply
   1,118.58x = 1,543.71 × 621.33
4. Step 4: Simplify right side
   1,118.58x = 959,153.33
5. Step 5: Solve for x
   x = 959,153.33/1,118.58
6. Step 6: Final answer
   x = 857.47