Finding the Fourth Proportional to 11,145.78, 16,721.37 and 5,585.31

Step by Step Solution

1. Step 1: Write the proportion equation
   11,145.78 : 16,721.37 = 5,585.31 : x
2. Step 2: Convert to fraction form
   11,145.78/16,721.37 = 5,585.31/x
3. Step 3: Cross multiply
   11,145.78x = 16,721.37 × 5,585.31
4. Step 4: Simplify right side
   11,145.78x = 93,394,035.07
5. Step 5: Solve for x
   x = 93,394,035.07/11,145.78
6. Step 6: Final answer
   x = 8,379.32