Finding the Fourth Proportional to 10,519.86, 15,785.82 and 4,278.72

Step by Step Solution

1. Step 1: Write the proportion equation
   10,519.86 : 15,785.82 = 4,278.72 : x
2. Step 2: Convert to fraction form
   10,519.86/15,785.82 = 4,278.72/x
3. Step 3: Cross multiply
   10,519.86x = 15,785.82 × 4,278.72
4. Step 4: Simplify right side
   10,519.86x = 67,543,103.75
5. Step 5: Solve for x
   x = 67,543,103.75/10,519.86
6. Step 6: Final answer
   x = 6,420.53