Finding the Fourth Proportional to 13,288.78, 18,338.61 and 7,623.78

Step by Step Solution

1. Step 1: Write the proportion equation
   13,288.78 : 18,338.61 = 7,623.78 : x
2. Step 2: Convert to fraction form
   13,288.78/18,338.61 = 7,623.78/x
3. Step 3: Cross multiply
   13,288.78x = 18,338.61 × 7,623.78
4. Step 4: Simplify right side
   13,288.78x = 139,809,528.15
5. Step 5: Solve for x
   x = 139,809,528.15/13,288.78
6. Step 6: Final answer
   x = 10,520.87