Finding the Fourth Proportional to 9,863.92, 13,611.72 and 5,672.20

Step by Step Solution

1. Step 1: Write the proportion equation
   9,863.92 : 13,611.72 = 5,672.20 : x
2. Step 2: Convert to fraction form
   9,863.92/13,611.72 = 5,672.20/x
3. Step 3: Cross multiply
   9,863.92x = 13,611.72 × 5,672.20
4. Step 4: Simplify right side
   9,863.92x = 77,208,398.18
5. Step 5: Solve for x
   x = 77,208,398.18/9,863.92
6. Step 6: Final answer
   x = 7,827.35