Finding the Fourth Proportional to 7,764.72, 11,643.20 and 3,871.28

Step by Step Solution

1. Step 1: Write the proportion equation
   7,764.72 : 11,643.20 = 3,871.28 : x
2. Step 2: Convert to fraction form
   7,764.72/11,643.20 = 3,871.28/x
3. Step 3: Cross multiply
   7,764.72x = 11,643.20 × 3,871.28
4. Step 4: Simplify right side
   7,764.72x = 45,074,087.30
5. Step 5: Solve for x
   x = 45,074,087.30/7,764.72
6. Step 6: Final answer
   x = 5,804.99