Finding the Third Proportional to 13,638 and 20,365.50

Step by Step Solution

1. Step 1: Write the proportion equation
   13,638 : 20,365.50 = 20,365.50 : x
2. Step 2: Convert to fraction form
   13,638/20,365.50 = 20,365.50/x
3. Step 3: Cross multiply
   13,638x = 20,365.50 × 20,365.50
4. Step 4: Simplify right side
   13,638x = 414,753,590.25
5. Step 5: Solve for x
   x = 414,753,590.25/13,638
6. Step 6: Final answer
   x = 30,411.61