Finding the Fourth Proportional to 3,911.61, 5,397.82 and 2,142.88

Step by Step Solution

1. Step 1: Write the proportion equation
   3,911.61 : 5,397.82 = 2,142.88 : x
2. Step 2: Convert to fraction form
   3,911.61/5,397.82 = 2,142.88/x
3. Step 3: Cross multiply
   3,911.61x = 5,397.82 × 2,142.88
4. Step 4: Simplify right side
   3,911.61x = 11,566,880.52
5. Step 5: Solve for x
   x = 11,566,880.52/3,911.61
6. Step 6: Final answer
   x = 2,957.06