Finding the Fourth Proportional to 3,721, 5,581.42 and 3,139.72

Step by Step Solution

1. Step 1: Write the proportion equation
   3,721 : 5,581.42 = 3,139.72 : x
2. Step 2: Convert to fraction form
   3,721/5,581.42 = 3,139.72/x
3. Step 3: Cross multiply
   3,721x = 5,581.42 × 3,139.72
4. Step 4: Simplify right side
   3,721x = 17,524,096.00
5. Step 5: Solve for x
   x = 17,524,096.00/3,721
6. Step 6: Final answer
   x = 4,709.51