Finding the Third Proportional to 6,390 and 10,611

Step by Step Solution

1. Step 1: Write the proportion equation
   6,390 : 10,611 = 10,611 : x
2. Step 2: Convert to fraction form
   6,390/10,611 = 10,611/x
3. Step 3: Cross multiply
   6,390x = 10,611 × 10,611
4. Step 4: Simplify right side
   6,390x = 112,593,321
5. Step 5: Solve for x
   x = 112,593,321/6,390
6. Step 6: Final answer
   x = 17,620.24