Finding the Fourth Proportional to 13,738.86, 18,958.61 and 7,688.31

Step by Step Solution

1. Step 1: Write the proportion equation
   13,738.86 : 18,958.61 = 7,688.31 : x
2. Step 2: Convert to fraction form
   13,738.86/18,958.61 = 7,688.31/x
3. Step 3: Cross multiply
   13,738.86x = 18,958.61 × 7,688.31
4. Step 4: Simplify right side
   13,738.86x = 145,759,670.85
5. Step 5: Solve for x
   x = 145,759,670.85/13,738.86
6. Step 6: Final answer
   x = 10,609.30