Finding the Fourth Proportional to 21,150.52, 31,728.71 and 7,111.65

Step by Step Solution

1. Step 1: Write the proportion equation
   21,150.52 : 31,728.71 = 7,111.65 : x
2. Step 2: Convert to fraction form
   21,150.52/31,728.71 = 7,111.65/x
3. Step 3: Cross multiply
   21,150.52x = 31,728.71 × 7,111.65
4. Step 4: Simplify right side
   21,150.52x = 225,643,480.47
5. Step 5: Solve for x
   x = 225,643,480.47/21,150.52
6. Step 6: Final answer
   x = 10,668.46