Finding the Fourth Proportional to 9,866.88, 13,616.42 and 5,390.69

Step by Step Solution

1. Step 1: Write the proportion equation
   9,866.88 : 13,616.42 = 5,390.69 : x
2. Step 2: Convert to fraction form
   9,866.88/13,616.42 = 5,390.69/x
3. Step 3: Cross multiply
   9,866.88x = 13,616.42 × 5,390.69
4. Step 4: Simplify right side
   9,866.88x = 73,401,804.09
5. Step 5: Solve for x
   x = 73,401,804.09/9,866.88
6. Step 6: Final answer
   x = 7,439.21