Finding the Fourth Proportional to 9,886.31, 13,643.91 and 5,638.71

Step by Step Solution

1. Step 1: Write the proportion equation
   9,886.31 : 13,643.91 = 5,638.71 : x
2. Step 2: Convert to fraction form
   9,886.31/13,643.91 = 5,638.71/x
3. Step 3: Cross multiply
   9,886.31x = 13,643.91 × 5,638.71
4. Step 4: Simplify right side
   9,886.31x = 76,933,983.54
5. Step 5: Solve for x
   x = 76,933,983.54/9,886.31
6. Step 6: Final answer
   x = 7,781.87