Finding the Third Proportional to 8,404 and 18,390

Step by Step Solution

1. Step 1: Write the proportion equation
   8,404 : 18,390 = 18,390 : x
2. Step 2: Convert to fraction form
   8,404/18,390 = 18,390/x
3. Step 3: Cross multiply
   8,404x = 18,390 × 18,390
4. Step 4: Simplify right side
   8,404x = 338,192,100
5. Step 5: Solve for x
   x = 338,192,100/8,404
6. Step 6: Final answer
   x = 40,241.80