Finding the Fourth Proportional to 2,118.72, 3,178.25 and 558.71

Step by Step Solution

1. Step 1: Write the proportion equation
   2,118.72 : 3,178.25 = 558.71 : x
2. Step 2: Convert to fraction form
   2,118.72/3,178.25 = 558.71/x
3. Step 3: Cross multiply
   2,118.72x = 3,178.25 × 558.71
4. Step 4: Simplify right side
   2,118.72x = 1,775,701.37
5. Step 5: Solve for x
   x = 1,775,701.37/2,118.72
6. Step 6: Final answer
   x = 838.10