Finding the Third Proportional to 13,639.50 and 18,663.75

Step by Step Solution

1. Step 1: Write the proportion equation
   13,639.50 : 18,663.75 = 18,663.75 : x
2. Step 2: Convert to fraction form
   13,639.50/18,663.75 = 18,663.75/x
3. Step 3: Cross multiply
   13,639.50x = 18,663.75 × 18,663.75
4. Step 4: Simplify right side
   13,639.50x = 348,335,564.06
5. Step 5: Solve for x
   x = 348,335,564.06/13,639.50
6. Step 6: Final answer
   x = 25,538.73