Finding the Fourth Proportional to 3,978.68, 5,485.59 and 2,559.86

Step by Step Solution

1. Step 1: Write the proportion equation
   3,978.68 : 5,485.59 = 2,559.86 : x
2. Step 2: Convert to fraction form
   3,978.68/5,485.59 = 2,559.86/x
3. Step 3: Cross multiply
   3,978.68x = 5,485.59 × 2,559.86
4. Step 4: Simplify right side
   3,978.68x = 14,042,314.99
5. Step 5: Solve for x
   x = 14,042,314.99/3,978.68
6. Step 6: Final answer
   x = 3,529.39