Finding the Fourth Proportional to 2,478.78, 3,420.54 and 1,818.42

Step by Step Solution

1. Step 1: Write the proportion equation
   2,478.78 : 3,420.54 = 1,818.42 : x
2. Step 2: Convert to fraction form
   2,478.78/3,420.54 = 1,818.42/x
3. Step 3: Cross multiply
   2,478.78x = 3,420.54 × 1,818.42
4. Step 4: Simplify right side
   2,478.78x = 6,219,978.35
5. Step 5: Solve for x
   x = 6,219,978.35/2,478.78
6. Step 6: Final answer
   x = 2,509.29