Finding the Fourth Proportional to 12,882.78, 17,774.20 and 7,216.76

Step by Step Solution

1. Step 1: Write the proportion equation
   12,882.78 : 17,774.20 = 7,216.76 : x
2. Step 2: Convert to fraction form
   12,882.78/17,774.20 = 7,216.76/x
3. Step 3: Cross multiply
   12,882.78x = 17,774.20 × 7,216.76
4. Step 4: Simplify right side
   12,882.78x = 128,272,189.05
5. Step 5: Solve for x
   x = 128,272,189.05/12,882.78
6. Step 6: Final answer
   x = 9,956.87