Finding the Fourth Proportional to 12,802.72, 19,212.79 and 7,857.27

Step by Step Solution

1. Step 1: Write the proportion equation
   12,802.72 : 19,212.79 = 7,857.27 : x
2. Step 2: Convert to fraction form
   12,802.72/19,212.79 = 7,857.27/x
3. Step 3: Cross multiply
   12,802.72x = 19,212.79 × 7,857.27
4. Step 4: Simplify right side
   12,802.72x = 150,960,078.48
5. Step 5: Solve for x
   x = 150,960,078.48/12,802.72
6. Step 6: Final answer
   x = 11,791.25