Finding the Fourth Proportional to 12,686.29, 19,031.27 and 3,921.89

Step by Step Solution

1. Step 1: Write the proportion equation
   12,686.29 : 19,031.27 = 3,921.89 : x
2. Step 2: Convert to fraction form
   12,686.29/19,031.27 = 3,921.89/x
3. Step 3: Cross multiply
   12,686.29x = 19,031.27 × 3,921.89
4. Step 4: Simplify right side
   12,686.29x = 74,638,432.73
5. Step 5: Solve for x
   x = 74,638,432.73/12,686.29
6. Step 6: Final answer
   x = 5,883.39