Finding the Fourth Proportional to 21,142.42, 29,169.92 and 12,188.71

Step by Step Solution

1. Step 1: Write the proportion equation
   21,142.42 : 29,169.92 = 12,188.71 : x
2. Step 2: Convert to fraction form
   21,142.42/29,169.92 = 12,188.71/x
3. Step 3: Cross multiply
   21,142.42x = 29,169.92 × 12,188.71
4. Step 4: Simplify right side
   21,142.42x = 355,543,762.54
5. Step 5: Solve for x
   x = 355,543,762.54/21,142.42
6. Step 6: Final answer
   x = 16,816.61