Finding the Fourth Proportional to 9,919.16, 13,688.74 and 5,443.20

Step by Step Solution

1. Step 1: Write the proportion equation
   9,919.16 : 13,688.74 = 5,443.20 : x
2. Step 2: Convert to fraction form
   9,919.16/13,688.74 = 5,443.20/x
3. Step 3: Cross multiply
   9,919.16x = 13,688.74 × 5,443.20
4. Step 4: Simplify right side
   9,919.16x = 74,510,474.42
5. Step 5: Solve for x
   x = 74,510,474.42/9,919.16
6. Step 6: Final answer
   x = 7,511.78