Finding the Fourth Proportional to 12,864.35, 19,328.83 and 8,186.40

Step by Step Solution

1. Step 1: Write the proportion equation
   12,864.35 : 19,328.83 = 8,186.40 : x
2. Step 2: Convert to fraction form
   12,864.35/19,328.83 = 8,186.40/x
3. Step 3: Cross multiply
   12,864.35x = 19,328.83 × 8,186.40
4. Step 4: Simplify right side
   12,864.35x = 158,233,513.45
5. Step 5: Solve for x
   x = 158,233,513.45/12,864.35
6. Step 6: Final answer
   x = 12,300.15