Finding the Fourth Proportional to 3,911.15, 5,397.57 and 2,142.72

Step by Step Solution

1. Step 1: Write the proportion equation
   3,911.15 : 5,397.57 = 2,142.72 : x
2. Step 2: Convert to fraction form
   3,911.15/5,397.57 = 2,142.72/x
3. Step 3: Cross multiply
   3,911.15x = 5,397.57 × 2,142.72
4. Step 4: Simplify right side
   3,911.15x = 11,565,481.19
5. Step 5: Solve for x
   x = 11,565,481.19/3,911.15
6. Step 6: Final answer
   x = 2,957.05