Finding the Fourth Proportional to 8,581.48, 12,820.21 and 5,436.32

Step by Step Solution

1. Step 1: Write the proportion equation
   8,581.48 : 12,820.21 = 5,436.32 : x
2. Step 2: Convert to fraction form
   8,581.48/12,820.21 = 5,436.32/x
3. Step 3: Cross multiply
   8,581.48x = 12,820.21 × 5,436.32
4. Step 4: Simplify right side
   8,581.48x = 69,694,686.34
5. Step 5: Solve for x
   x = 69,694,686.34/8,581.48
6. Step 6: Final answer
   x = 8,121.53