Finding the Fourth Proportional to 6,139.86, 8,470.42 and 3,780.63

Step by Step Solution

1. Step 1: Write the proportion equation
   6,139.86 : 8,470.42 = 3,780.63 : x
2. Step 2: Convert to fraction form
   6,139.86/8,470.42 = 3,780.63/x
3. Step 3: Cross multiply
   6,139.86x = 8,470.42 × 3,780.63
4. Step 4: Simplify right side
   6,139.86x = 32,023,523.96
5. Step 5: Solve for x
   x = 32,023,523.96/6,139.86
6. Step 6: Final answer
   x = 5,215.68