Finding the Third Proportional to 5,108 and 10,431

Step by Step Solution

1. Step 1: Write the proportion equation
   5,108 : 10,431 = 10,431 : x
2. Step 2: Convert to fraction form
   5,108/10,431 = 10,431/x
3. Step 3: Cross multiply
   5,108x = 10,431 × 10,431
4. Step 4: Simplify right side
   5,108x = 108,805,761
5. Step 5: Solve for x
   x = 108,805,761/5,108
6. Step 6: Final answer
   x = 21,301.05