Finding the Fourth Proportional to 10,520.74, 15,783.86 and 3,947.05

Step by Step Solution

1. Step 1: Write the proportion equation
   10,520.74 : 15,783.86 = 3,947.05 : x
2. Step 2: Convert to fraction form
   10,520.74/15,783.86 = 3,947.05/x
3. Step 3: Cross multiply
   10,520.74x = 15,783.86 × 3,947.05
4. Step 4: Simplify right side
   10,520.74x = 62,299,684.61
5. Step 5: Solve for x
   x = 62,299,684.61/10,520.74
6. Step 6: Final answer
   x = 5,921.61