Finding the Third Proportional to 10,390 and 13,143

Step by Step Solution

1. Step 1: Write the proportion equation
   10,390 : 13,143 = 13,143 : x
2. Step 2: Convert to fraction form
   10,390/13,143 = 13,143/x
3. Step 3: Cross multiply
   10,390x = 13,143 × 13,143
4. Step 4: Simplify right side
   10,390x = 172,738,449
5. Step 5: Solve for x
   x = 172,738,449/10,390
6. Step 6: Final answer
   x = 16,625.45