Finding the Third Proportional to 8,436 and 12,490

Step by Step Solution

1. Step 1: Write the proportion equation
   8,436 : 12,490 = 12,490 : x
2. Step 2: Convert to fraction form
   8,436/12,490 = 12,490/x
3. Step 3: Cross multiply
   8,436x = 12,490 × 12,490
4. Step 4: Simplify right side
   8,436x = 156,000,100
5. Step 5: Solve for x
   x = 156,000,100/8,436
6. Step 6: Final answer
   x = 18,492.19