Finding the Fourth Proportional to 10,116.72, 13,959.84 and 5,640.72

Step by Step Solution

1. Step 1: Write the proportion equation
   10,116.72 : 13,959.84 = 5,640.72 : x
2. Step 2: Convert to fraction form
   10,116.72/13,959.84 = 5,640.72/x
3. Step 3: Cross multiply
   10,116.72x = 13,959.84 × 5,640.72
4. Step 4: Simplify right side
   10,116.72x = 78,743,548.68
5. Step 5: Solve for x
   x = 78,743,548.68/10,116.72
6. Step 6: Final answer
   x = 7,783.51