Finding the Third Proportional to 8,431.50 and 12,280.50

Step by Step Solution

1. Step 1: Write the proportion equation
   8,431.50 : 12,280.50 = 12,280.50 : x
2. Step 2: Convert to fraction form
   8,431.50/12,280.50 = 12,280.50/x
3. Step 3: Cross multiply
   8,431.50x = 12,280.50 × 12,280.50
4. Step 4: Simplify right side
   8,431.50x = 150,810,680.25
5. Step 5: Solve for x
   x = 150,810,680.25/8,431.50
6. Step 6: Final answer
   x = 17,886.58