Finding the Fourth Proportional to 9,221.29, 12,726.77 and 5,638.31

Step by Step Solution

1. Step 1: Write the proportion equation
   9,221.29 : 12,726.77 = 5,638.31 : x
2. Step 2: Convert to fraction form
   9,221.29/12,726.77 = 5,638.31/x
3. Step 3: Cross multiply
   9,221.29x = 12,726.77 × 5,638.31
4. Step 4: Simplify right side
   9,221.29x = 71,757,462.17
5. Step 5: Solve for x
   x = 71,757,462.17/9,221.29
6. Step 6: Final answer
   x = 7,781.71