Finding the Fourth Proportional to 12,500.21, 18,728.78 and 8,280.83

Step by Step Solution

1. Step 1: Write the proportion equation
   12,500.21 : 18,728.78 = 8,280.83 : x
2. Step 2: Convert to fraction form
   12,500.21/18,728.78 = 8,280.83/x
3. Step 3: Cross multiply
   12,500.21x = 18,728.78 × 8,280.83
4. Step 4: Simplify right side
   12,500.21x = 155,089,848.71
5. Step 5: Solve for x
   x = 155,089,848.71/12,500.21
6. Step 6: Final answer
   x = 12,406.98