Finding the Third Proportional to 10,138 and 19,988

Step by Step Solution

1. Step 1: Write the proportion equation
   10,138 : 19,988 = 19,988 : x
2. Step 2: Convert to fraction form
   10,138/19,988 = 19,988/x
3. Step 3: Cross multiply
   10,138x = 19,988 × 19,988
4. Step 4: Simplify right side
   10,138x = 399,520,144
5. Step 5: Solve for x
   x = 399,520,144/10,138
6. Step 6: Final answer
   x = 39,408.18