Finding the Fourth Proportional to 3,969.21, 5,479.98 and 2,555.34

Step by Step Solution

1. Step 1: Write the proportion equation
   3,969.21 : 5,479.98 = 2,555.34 : x
2. Step 2: Convert to fraction form
   3,969.21/5,479.98 = 2,555.34/x
3. Step 3: Cross multiply
   3,969.21x = 5,479.98 × 2,555.34
4. Step 4: Simplify right side
   3,969.21x = 14,003,215.75
5. Step 5: Solve for x
   x = 14,003,215.75/3,969.21
6. Step 6: Final answer
   x = 3,527.96