Finding the Fourth Proportional to 12,764.72, 17,615.52 and 7,728.88

Step by Step Solution

1. Step 1: Write the proportion equation
   12,764.72 : 17,615.52 = 7,728.88 : x
2. Step 2: Convert to fraction form
   12,764.72/17,615.52 = 7,728.88/x
3. Step 3: Cross multiply
   12,764.72x = 17,615.52 × 7,728.88
4. Step 4: Simplify right side
   12,764.72x = 136,148,240.22
5. Step 5: Solve for x
   x = 136,148,240.22/12,764.72
6. Step 6: Final answer
   x = 10,665.98