Finding the Fourth Proportional to 12,758.31, 19,140.71 and 3,993.30

Step by Step Solution

1. Step 1: Write the proportion equation
   12,758.31 : 19,140.71 = 3,993.30 : x
2. Step 2: Convert to fraction form
   12,758.31/19,140.71 = 3,993.30/x
3. Step 3: Cross multiply
   12,758.31x = 19,140.71 × 3,993.30
4. Step 4: Simplify right side
   12,758.31x = 76,434,577.28
5. Step 5: Solve for x
   x = 76,434,577.28/12,758.31
6. Step 6: Final answer
   x = 5,990.96