Finding the Fourth Proportional to 3,425.72, 5,138.78 and 1,085.81

Step by Step Solution

1. Step 1: Write the proportion equation
   3,425.72 : 5,138.78 = 1,085.81 : x
2. Step 2: Convert to fraction form
   3,425.72/5,138.78 = 1,085.81/x
3. Step 3: Cross multiply
   3,425.72x = 5,138.78 × 1,085.81
4. Step 4: Simplify right side
   3,425.72x = 5,579,707.59
5. Step 5: Solve for x
   x = 5,579,707.59/3,425.72
6. Step 6: Final answer
   x = 1,628.77