Finding the Fourth Proportional to 9,920.15, 13,689.80 and 5,443.92

Step by Step Solution

1. Step 1: Write the proportion equation
   9,920.15 : 13,689.80 = 5,443.92 : x
2. Step 2: Convert to fraction form
   9,920.15/13,689.80 = 5,443.92/x
3. Step 3: Cross multiply
   9,920.15x = 13,689.80 × 5,443.92
4. Step 4: Simplify right side
   9,920.15x = 74,526,176.02
5. Step 5: Solve for x
   x = 74,526,176.02/9,920.15
6. Step 6: Final answer
   x = 7,512.61