Finding the Fourth Proportional to 3,978.94, 5,490.94 and 2,210.71

Step by Step Solution

1. Step 1: Write the proportion equation
   3,978.94 : 5,490.94 = 2,210.71 : x
2. Step 2: Convert to fraction form
   3,978.94/5,490.94 = 2,210.71/x
3. Step 3: Cross multiply
   3,978.94x = 5,490.94 × 2,210.71
4. Step 4: Simplify right side
   3,978.94x = 12,138,856.71
5. Step 5: Solve for x
   x = 12,138,856.71/3,978.94
6. Step 6: Final answer
   x = 3,050.78