Finding the Fourth Proportional to 21,111.92, 31,658.64 and 10,021.80

Step by Step Solution

1. Step 1: Write the proportion equation
   21,111.92 : 31,658.64 = 10,021.80 : x
2. Step 2: Convert to fraction form
   21,111.92/31,658.64 = 10,021.80/x
3. Step 3: Cross multiply
   21,111.92x = 31,658.64 × 10,021.80
4. Step 4: Simplify right side
   21,111.92x = 317,276,558.35
5. Step 5: Solve for x
   x = 317,276,558.35/21,111.92
6. Step 6: Final answer
   x = 15,028.31