Finding the Fourth Proportional to 9,339.91, 12,888.72 and 5,090.85

Step by Step Solution

1. Step 1: Write the proportion equation
   9,339.91 : 12,888.72 = 5,090.85 : x
2. Step 2: Convert to fraction form
   9,339.91/12,888.72 = 5,090.85/x
3. Step 3: Cross multiply
   9,339.91x = 12,888.72 × 5,090.85
4. Step 4: Simplify right side
   9,339.91x = 65,614,540.21
5. Step 5: Solve for x
   x = 65,614,540.21/9,339.91
6. Step 6: Final answer
   x = 7,025.18