Finding the Fourth Proportional to 7,105.72, 9,805.76 and 3,919.31

Step by Step Solution

1. Step 1: Write the proportion equation
   7,105.72 : 9,805.76 = 3,919.31 : x
2. Step 2: Convert to fraction form
   7,105.72/9,805.76 = 3,919.31/x
3. Step 3: Cross multiply
   7,105.72x = 9,805.76 × 3,919.31
4. Step 4: Simplify right side
   7,105.72x = 38,431,744.60
5. Step 5: Solve for x
   x = 38,431,744.60/7,105.72
6. Step 6: Final answer
   x = 5,408.57