Finding the Fourth Proportional to 8,643.72, 12,960.96 and 2,719.50

Step by Step Solution

1. Step 1: Write the proportion equation
   8,643.72 : 12,960.96 = 2,719.50 : x
2. Step 2: Convert to fraction form
   8,643.72/12,960.96 = 2,719.50/x
3. Step 3: Cross multiply
   8,643.72x = 12,960.96 × 2,719.50
4. Step 4: Simplify right side
   8,643.72x = 35,247,330.72
5. Step 5: Solve for x
   x = 35,247,330.72/8,643.72
6. Step 6: Final answer
   x = 4,077.80