Finding the Fourth Proportional to 3,978.32, 5,490.58 and 2,406.42

Step by Step Solution

1. Step 1: Write the proportion equation
   3,978.32 : 5,490.58 = 2,406.42 : x
2. Step 2: Convert to fraction form
   3,978.32/5,490.58 = 2,406.42/x
3. Step 3: Cross multiply
   3,978.32x = 5,490.58 × 2,406.42
4. Step 4: Simplify right side
   3,978.32x = 13,212,641.52
5. Step 5: Solve for x
   x = 13,212,641.52/3,978.32
6. Step 6: Final answer
   x = 3,321.16