Finding the Third Proportional to 10,440 and 13,221

Step by Step Solution

1. Step 1: Write the proportion equation
   10,440 : 13,221 = 13,221 : x
2. Step 2: Convert to fraction form
   10,440/13,221 = 13,221/x
3. Step 3: Cross multiply
   10,440x = 13,221 × 13,221
4. Step 4: Simplify right side
   10,440x = 174,794,841
5. Step 5: Solve for x
   x = 174,794,841/10,440
6. Step 6: Final answer
   x = 16,742.80