Finding the Fourth Proportional to 9,920.21, 13,689.86 and 5,443.88

Step by Step Solution

1. Step 1: Write the proportion equation
   9,920.21 : 13,689.86 = 5,443.88 : x
2. Step 2: Convert to fraction form
   9,920.21/13,689.86 = 5,443.88/x
3. Step 3: Cross multiply
   9,920.21x = 13,689.86 × 5,443.88
4. Step 4: Simplify right side
   9,920.21x = 74,525,859.39
5. Step 5: Solve for x
   x = 74,525,859.39/9,920.21
6. Step 6: Final answer
   x = 7,512.53