Finding the Fourth Proportional to 8,856.36, 12,221.46 and 5,715.72

Step by Step Solution

1. Step 1: Write the proportion equation
   8,856.36 : 12,221.46 = 5,715.72 : x
2. Step 2: Convert to fraction form
   8,856.36/12,221.46 = 5,715.72/x
3. Step 3: Cross multiply
   8,856.36x = 12,221.46 × 5,715.72
4. Step 4: Simplify right side
   8,856.36x = 69,854,443.35
5. Step 5: Solve for x
   x = 69,854,443.35/8,856.36
6. Step 6: Final answer
   x = 7,887.49