Finding the Fourth Proportional to 8,256.76, 12,389.42 and 5,485.36

Step by Step Solution

1. Step 1: Write the proportion equation
   8,256.76 : 12,389.42 = 5,485.36 : x
2. Step 2: Convert to fraction form
   8,256.76/12,389.42 = 5,485.36/x
3. Step 3: Cross multiply
   8,256.76x = 12,389.42 × 5,485.36
4. Step 4: Simplify right side
   8,256.76x = 67,960,428.89
5. Step 5: Solve for x
   x = 67,960,428.89/8,256.76
6. Step 6: Final answer
   x = 8,230.88