Finding the Fourth Proportional to 21,105.40, 31,653.78 and 7,255.48

Step by Step Solution

1. Step 1: Write the proportion equation
   21,105.40 : 31,653.78 = 7,255.48 : x
2. Step 2: Convert to fraction form
   21,105.40/31,653.78 = 7,255.48/x
3. Step 3: Cross multiply
   21,105.40x = 31,653.78 × 7,255.48
4. Step 4: Simplify right side
   21,105.40x = 229,663,367.71
5. Step 5: Solve for x
   x = 229,663,367.71/21,105.40
6. Step 6: Final answer
   x = 10,881.73