Finding the Fourth Proportional to 3,978.96, 5,491 and 2,210.60

Step by Step Solution

1. Step 1: Write the proportion equation
   3,978.96 : 5,491 = 2,210.60 : x
2. Step 2: Convert to fraction form
   3,978.96/5,491 = 2,210.60/x
3. Step 3: Cross multiply
   3,978.96x = 5,491 × 2,210.60
4. Step 4: Simplify right side
   3,978.96x = 12,138,404.60
5. Step 5: Solve for x
   x = 12,138,404.60/3,978.96
6. Step 6: Final answer
   x = 3,050.65