Finding the Fourth Proportional to 13,399.72, 18,488.10 and 7,806.76

Step by Step Solution

1. Step 1: Write the proportion equation
   13,399.72 : 18,488.10 = 7,806.76 : x
2. Step 2: Convert to fraction form
   13,399.72/18,488.10 = 7,806.76/x
3. Step 3: Cross multiply
   13,399.72x = 18,488.10 × 7,806.76
4. Step 4: Simplify right side
   13,399.72x = 144,332,159.56
5. Step 5: Solve for x
   x = 144,332,159.56/13,399.72
6. Step 6: Final answer
   x = 10,771.28