Finding the Fourth Proportional to 21,197, 31,781.46 and 10,105.40

Step by Step Solution

1. Step 1: Write the proportion equation
   21,197 : 31,781.46 = 10,105.40 : x
2. Step 2: Convert to fraction form
   21,197/31,781.46 = 10,105.40/x
3. Step 3: Cross multiply
   21,197x = 31,781.46 × 10,105.40
4. Step 4: Simplify right side
   21,197x = 321,164,365.88
5. Step 5: Solve for x
   x = 321,164,365.88/21,197
6. Step 6: Final answer
   x = 15,151.41