Finding the Fourth Proportional to 21,831.69, 30,126.42 and 12,882

Step by Step Solution

1. Step 1: Write the proportion equation
   21,831.69 : 30,126.42 = 12,882 : x
2. Step 2: Convert to fraction form
   21,831.69/30,126.42 = 12,882/x
3. Step 3: Cross multiply
   21,831.69x = 30,126.42 × 12,882
4. Step 4: Simplify right side
   21,831.69x = 388,088,542.44
5. Step 5: Solve for x
   x = 388,088,542.44/21,831.69
6. Step 6: Final answer
   x = 17,776.39