Finding the Fourth Proportional to 9,865.45, 13,605.83 and 8,790.17

Step by Step Solution

1. Step 1: Write the proportion equation
   9,865.45 : 13,605.83 = 8,790.17 : x
2. Step 2: Convert to fraction form
   9,865.45/13,605.83 = 8,790.17/x
3. Step 3: Cross multiply
   9,865.45x = 13,605.83 × 8,790.17
4. Step 4: Simplify right side
   9,865.45x = 119,597,581.72
5. Step 5: Solve for x
   x = 119,597,581.72/9,865.45
6. Step 6: Final answer
   x = 12,122.87