Finding the Fourth Proportional to 21,151.88, 31,728.33 and 7,112.09

Step by Step Solution

1. Step 1: Write the proportion equation
   21,151.88 : 31,728.33 = 7,112.09 : x
2. Step 2: Convert to fraction form
   21,151.88/31,728.33 = 7,112.09/x
3. Step 3: Cross multiply
   21,151.88x = 31,728.33 × 7,112.09
4. Step 4: Simplify right side
   21,151.88x = 225,654,544.31
5. Step 5: Solve for x
   x = 225,654,544.31/21,151.88
6. Step 6: Final answer
   x = 10,668.30