Finding the Fourth Proportional to 23,420.48, 35,144.55 and 8,639.72

Step by Step Solution

1. Step 1: Write the proportion equation
   23,420.48 : 35,144.55 = 8,639.72 : x
2. Step 2: Convert to fraction form
   23,420.48/35,144.55 = 8,639.72/x
3. Step 3: Cross multiply
   23,420.48x = 35,144.55 × 8,639.72
4. Step 4: Simplify right side
   23,420.48x = 303,639,071.53
5. Step 5: Solve for x
   x = 303,639,071.53/23,420.48
6. Step 6: Final answer
   x = 12,964.68