Finding the Fourth Proportional to 13,142.48, 19,721.49 and 12,311.27

Step by Step Solution

1. Step 1: Write the proportion equation
   13,142.48 : 19,721.49 = 12,311.27 : x
2. Step 2: Convert to fraction form
   13,142.48/19,721.49 = 12,311.27/x
3. Step 3: Cross multiply
   13,142.48x = 19,721.49 × 12,311.27
4. Step 4: Simplify right side
   13,142.48x = 242,796,588.19
5. Step 5: Solve for x
   x = 242,796,588.19/13,142.48
6. Step 6: Final answer
   x = 18,474.18