Finding the Fourth Proportional to 9,919.72, 13,689.16 and 5,443.36

Step by Step Solution

1. Step 1: Write the proportion equation
   9,919.72 : 13,689.16 = 5,443.36 : x
2. Step 2: Convert to fraction form
   9,919.72/13,689.16 = 5,443.36/x
3. Step 3: Cross multiply
   9,919.72x = 13,689.16 × 5,443.36
4. Step 4: Simplify right side
   9,919.72x = 74,515,025.98
5. Step 5: Solve for x
   x = 74,515,025.98/9,919.72
6. Step 6: Final answer
   x = 7,511.81