Finding the Fourth Proportional to 9,919.56, 13,688.76 and 5,443.20

Step by Step Solution

1. Step 1: Write the proportion equation
   9,919.56 : 13,688.76 = 5,443.20 : x
2. Step 2: Convert to fraction form
   9,919.56/13,688.76 = 5,443.20/x
3. Step 3: Cross multiply
   9,919.56x = 13,688.76 × 5,443.20
4. Step 4: Simplify right side
   9,919.56x = 74,510,658.43
5. Step 5: Solve for x
   x = 74,510,658.43/9,919.56
6. Step 6: Final answer
   x = 7,511.49