Finding the Fourth Proportional to 3,978.30, 5,490.06 and 2,209.86

Step by Step Solution

1. Step 1: Write the proportion equation
   3,978.30 : 5,490.06 = 2,209.86 : x
2. Step 2: Convert to fraction form
   3,978.30/5,490.06 = 2,209.86/x
3. Step 3: Cross multiply
   3,978.30x = 5,490.06 × 2,209.86
4. Step 4: Simplify right side
   3,978.30x = 12,132,263.99
5. Step 5: Solve for x
   x = 12,132,263.99/3,978.30
6. Step 6: Final answer
   x = 3,049.61