Finding the Fourth Proportional to 9,866.56, 13,616.05 and 5,390.50

Step by Step Solution

1. Step 1: Write the proportion equation
   9,866.56 : 13,616.05 = 5,390.50 : x
2. Step 2: Convert to fraction form
   9,866.56/13,616.05 = 5,390.50/x
3. Step 3: Cross multiply
   9,866.56x = 13,616.05 × 5,390.50
4. Step 4: Simplify right side
   9,866.56x = 73,397,305.65
5. Step 5: Solve for x
   x = 73,397,305.65/9,866.56
6. Step 6: Final answer
   x = 7,439.00