Finding the Fourth Proportional to 13,662.96, 18,731.99 and 13,413.89

Step by Step Solution

1. Step 1: Write the proportion equation
   13,662.96 : 18,731.99 = 13,413.89 : x
2. Step 2: Convert to fraction form
   13,662.96/18,731.99 = 13,413.89/x
3. Step 3: Cross multiply
   13,662.96x = 18,731.99 × 13,413.89
4. Step 4: Simplify right side
   13,662.96x = 251,268,692.61
5. Step 5: Solve for x
   x = 251,268,692.61/13,662.96
6. Step 6: Final answer
   x = 18,390.50