Finding the Fourth Proportional to 11,387.33, 15,721.82 and 7,144.20

Step by Step Solution

1. Step 1: Write the proportion equation
   11,387.33 : 15,721.82 = 7,144.20 : x
2. Step 2: Convert to fraction form
   11,387.33/15,721.82 = 7,144.20/x
3. Step 3: Cross multiply
   11,387.33x = 15,721.82 × 7,144.20
4. Step 4: Simplify right side
   11,387.33x = 112,319,790.72
5. Step 5: Solve for x
   x = 112,319,790.72/11,387.33
6. Step 6: Final answer
   x = 9,863.58