Finding the Fourth Proportional to 3,907.72, 5,392.71 and 2,139.29

Step by Step Solution

1. Step 1: Write the proportion equation
   3,907.72 : 5,392.71 = 2,139.29 : x
2. Step 2: Convert to fraction form
   3,907.72/5,392.71 = 2,139.29/x
3. Step 3: Cross multiply
   3,907.72x = 5,392.71 × 2,139.29
4. Step 4: Simplify right side
   3,907.72x = 11,536,570.58
5. Step 5: Solve for x
   x = 11,536,570.58/3,907.72
6. Step 6: Final answer
   x = 2,952.25