Finding the Fourth Proportional to 3,425.31, 5,138.59 and 1,085.90

Step by Step Solution

1. Step 1: Write the proportion equation
   3,425.31 : 5,138.59 = 1,085.90 : x
2. Step 2: Convert to fraction form
   3,425.31/5,138.59 = 1,085.90/x
3. Step 3: Cross multiply
   3,425.31x = 5,138.59 × 1,085.90
4. Step 4: Simplify right side
   3,425.31x = 5,579,994.88
5. Step 5: Solve for x
   x = 5,579,994.88/3,425.31
6. Step 6: Final answer
   x = 1,629.05