Finding the Fourth Proportional to 2,118.25, 3,178.71 and 819.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,118.25 : 3,178.71 = 819.72 : x
2. Step 2: Convert to fraction form
   2,118.25/3,178.71 = 819.72/x
3. Step 3: Cross multiply
   2,118.25x = 3,178.71 × 819.72
4. Step 4: Simplify right side
   2,118.25x = 2,605,652.16
5. Step 5: Solve for x
   x = 2,605,652.16/2,118.25
6. Step 6: Final answer
   x = 1,230.10