Finding the Fourth Proportional to 3,969.91, 5,478.42 and 2,201.55

Step by Step Solution

1. Step 1: Write the proportion equation
   3,969.91 : 5,478.42 = 2,201.55 : x
2. Step 2: Convert to fraction form
   3,969.91/5,478.42 = 2,201.55/x
3. Step 3: Cross multiply
   3,969.91x = 5,478.42 × 2,201.55
4. Step 4: Simplify right side
   3,969.91x = 12,061,015.55
5. Step 5: Solve for x
   x = 12,061,015.55/3,969.91
6. Step 6: Final answer
   x = 3,038.11