Finding the Third Proportional to 8,418 and 10,290

Step by Step Solution

1. Step 1: Write the proportion equation
   8,418 : 10,290 = 10,290 : x
2. Step 2: Convert to fraction form
   8,418/10,290 = 10,290/x
3. Step 3: Cross multiply
   8,418x = 10,290 × 10,290
4. Step 4: Simplify right side
   8,418x = 105,884,100
5. Step 5: Solve for x
   x = 105,884,100/8,418
6. Step 6: Final answer
   x = 12,578.30