Finding the Fourth Proportional to 8,619.76, 12,930.27 and 2,780.56

Step by Step Solution

1. Step 1: Write the proportion equation
   8,619.76 : 12,930.27 = 2,780.56 : x
2. Step 2: Convert to fraction form
   8,619.76/12,930.27 = 2,780.56/x
3. Step 3: Cross multiply
   8,619.76x = 12,930.27 × 2,780.56
4. Step 4: Simplify right side
   8,619.76x = 35,953,391.55
5. Step 5: Solve for x
   x = 35,953,391.55/8,619.76
6. Step 6: Final answer
   x = 4,171.04