Finding the Fourth Proportional to 9,899.31, 13,661.04 and 5,920.42

Step by Step Solution

1. Step 1: Write the proportion equation
   9,899.31 : 13,661.04 = 5,920.42 : x
2. Step 2: Convert to fraction form
   9,899.31/13,661.04 = 5,920.42/x
3. Step 3: Cross multiply
   9,899.31x = 13,661.04 × 5,920.42
4. Step 4: Simplify right side
   9,899.31x = 80,879,084.19
5. Step 5: Solve for x
   x = 80,879,084.19/9,899.31
6. Step 6: Final answer
   x = 8,170.18