Finding the Fourth Proportional to 12,399.36, 17,066.88 and 10,279.68

Step by Step Solution

1. Step 1: Write the proportion equation
   12,399.36 : 17,066.88 = 10,279.68 : x
2. Step 2: Convert to fraction form
   12,399.36/17,066.88 = 10,279.68/x
3. Step 3: Cross multiply
   12,399.36x = 17,066.88 × 10,279.68
4. Step 4: Simplify right side
   12,399.36x = 175,442,065.00
5. Step 5: Solve for x
   x = 175,442,065.00/12,399.36
6. Step 6: Final answer
   x = 14,149.28