Finding the Fourth Proportional to 8,665.30, 12,995.06 and 2,820.55

Step by Step Solution

1. Step 1: Write the proportion equation
   8,665.30 : 12,995.06 = 2,820.55 : x
2. Step 2: Convert to fraction form
   8,665.30/12,995.06 = 2,820.55/x
3. Step 3: Cross multiply
   8,665.30x = 12,995.06 × 2,820.55
4. Step 4: Simplify right side
   8,665.30x = 36,653,216.48
5. Step 5: Solve for x
   x = 36,653,216.48/8,665.30
6. Step 6: Final answer
   x = 4,229.88