Finding the Fourth Proportional to 3,421.43, 5,131.40 and 1,081.61

Step by Step Solution

1. Step 1: Write the proportion equation
   3,421.43 : 5,131.40 = 1,081.61 : x
2. Step 2: Convert to fraction form
   3,421.43/5,131.40 = 1,081.61/x
3. Step 3: Cross multiply
   3,421.43x = 5,131.40 × 1,081.61
4. Step 4: Simplify right side
   3,421.43x = 5,550,161.73
5. Step 5: Solve for x
   x = 5,550,161.73/3,421.43
6. Step 6: Final answer
   x = 1,622.18