Finding the Fourth Proportional to 11,686.15, 17,439.79 and 10,439.56

Step by Step Solution

1. Step 1: Write the proportion equation
   11,686.15 : 17,439.79 = 10,439.56 : x
2. Step 2: Convert to fraction form
   11,686.15/17,439.79 = 10,439.56/x
3. Step 3: Cross multiply
   11,686.15x = 17,439.79 × 10,439.56
4. Step 4: Simplify right side
   11,686.15x = 182,063,681.89
5. Step 5: Solve for x
   x = 182,063,681.89/11,686.15
6. Step 6: Final answer
   x = 15,579.44