Finding the Fourth Proportional to 21,128.48, 31,696.32 and 10,603.52

Step by Step Solution

1. Step 1: Write the proportion equation
   21,128.48 : 31,696.32 = 10,603.52 : x
2. Step 2: Convert to fraction form
   21,128.48/31,696.32 = 10,603.52/x
3. Step 3: Cross multiply
   21,128.48x = 31,696.32 × 10,603.52
4. Step 4: Simplify right side
   21,128.48x = 336,092,563.05
5. Step 5: Solve for x
   x = 336,092,563.05/21,128.48
6. Step 6: Final answer
   x = 15,907.09