Finding the Fourth Proportional to 10,389.63, 15,591.28 and 3,815.87

Step by Step Solution

1. Step 1: Write the proportion equation
   10,389.63 : 15,591.28 = 3,815.87 : x
2. Step 2: Convert to fraction form
   10,389.63/15,591.28 = 3,815.87/x
3. Step 3: Cross multiply
   10,389.63x = 15,591.28 × 3,815.87
4. Step 4: Simplify right side
   10,389.63x = 59,494,250.39
5. Step 5: Solve for x
   x = 59,494,250.39/10,389.63
6. Step 6: Final answer
   x = 5,726.31