Finding the Fourth Proportional to 7,142.61, 9,856.88 and 4,158.72

Step by Step Solution

1. Step 1: Write the proportion equation
   7,142.61 : 9,856.88 = 4,158.72 : x
2. Step 2: Convert to fraction form
   7,142.61/9,856.88 = 4,158.72/x
3. Step 3: Cross multiply
   7,142.61x = 9,856.88 × 4,158.72
4. Step 4: Simplify right side
   7,142.61x = 40,991,965.22
5. Step 5: Solve for x
   x = 40,991,965.22/7,142.61
6. Step 6: Final answer
   x = 5,739.08