Finding the Fourth Proportional to 2,485.86, 3,727.17 and 819.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,485.86 : 3,727.17 = 819.78 : x
2. Step 2: Convert to fraction form
   2,485.86/3,727.17 = 819.78/x
3. Step 3: Cross multiply
   2,485.86x = 3,727.17 × 819.78
4. Step 4: Simplify right side
   2,485.86x = 3,055,459.42
5. Step 5: Solve for x
   x = 3,055,459.42/2,485.86
6. Step 6: Final answer
   x = 1,229.14