Finding the Fourth Proportional to 3,908.16, 5,393.22 and 2,139.76

Step by Step Solution

1. Step 1: Write the proportion equation
   3,908.16 : 5,393.22 = 2,139.76 : x
2. Step 2: Convert to fraction form
   3,908.16/5,393.22 = 2,139.76/x
3. Step 3: Cross multiply
   3,908.16x = 5,393.22 × 2,139.76
4. Step 4: Simplify right side
   3,908.16x = 11,540,196.43
5. Step 5: Solve for x
   x = 11,540,196.43/3,908.16
6. Step 6: Final answer
   x = 2,952.85