Finding the Fourth Proportional to 4,088.78, 5,640.69 and 3,142.88

Step by Step Solution

1. Step 1: Write the proportion equation
   4,088.78 : 5,640.69 = 3,142.88 : x
2. Step 2: Convert to fraction form
   4,088.78/5,640.69 = 3,142.88/x
3. Step 3: Cross multiply
   4,088.78x = 5,640.69 × 3,142.88
4. Step 4: Simplify right side
   4,088.78x = 17,728,011.79
5. Step 5: Solve for x
   x = 17,728,011.79/4,088.78
6. Step 6: Final answer
   x = 4,335.77