Finding the Fourth Proportional to 3,581.78, 5,371.31 and 1,390.00

Step by Step Solution

1. Step 1: Write the proportion equation
   3,581.78 : 5,371.31 = 1,390.00 : x
2. Step 2: Convert to fraction form
   3,581.78/5,371.31 = 1,390.00/x
3. Step 3: Cross multiply
   3,581.78x = 5,371.31 × 1,390.00
4. Step 4: Simplify right side
   3,581.78x = 7,466,104.67
5. Step 5: Solve for x
   x = 7,466,104.67/3,581.78
6. Step 6: Final answer
   x = 2,084.47