Finding the Fourth Proportional to 12,866.72, 17,756.88 and 7,278.56

Step by Step Solution

1. Step 1: Write the proportion equation
   12,866.72 : 17,756.88 = 7,278.56 : x
2. Step 2: Convert to fraction form
   12,866.72/17,756.88 = 7,278.56/x
3. Step 3: Cross multiply
   12,866.72x = 17,756.88 × 7,278.56
4. Step 4: Simplify right side
   12,866.72x = 129,244,516.49
5. Step 5: Solve for x
   x = 129,244,516.49/12,866.72
6. Step 6: Final answer
   x = 10,044.87