Finding the Fourth Proportional to 12,786.96, 17,644.74 and 9,431.58

Step by Step Solution

1. Step 1: Write the proportion equation
   12,786.96 : 17,644.74 = 9,431.58 : x
2. Step 2: Convert to fraction form
   12,786.96/17,644.74 = 9,431.58/x
3. Step 3: Cross multiply
   12,786.96x = 17,644.74 × 9,431.58
4. Step 4: Simplify right side
   12,786.96x = 166,417,776.89
5. Step 5: Solve for x
   x = 166,417,776.89/12,786.96
6. Step 6: Final answer
   x = 13,014.65