Finding the Fourth Proportional to 20,900.28, 31,347.18 and 6,105.72

Step by Step Solution

1. Step 1: Write the proportion equation
   20,900.28 : 31,347.18 = 6,105.72 : x
2. Step 2: Convert to fraction form
   20,900.28/31,347.18 = 6,105.72/x
3. Step 3: Cross multiply
   20,900.28x = 31,347.18 × 6,105.72
4. Step 4: Simplify right side
   20,900.28x = 191,397,103.87
5. Step 5: Solve for x
   x = 191,397,103.87/20,900.28
6. Step 6: Final answer
   x = 9,157.63