Finding the Fourth Proportional to 3,907.98, 5,393.00 and 2,139.57

Step by Step Solution

1. Step 1: Write the proportion equation
   3,907.98 : 5,393.00 = 2,139.57 : x
2. Step 2: Convert to fraction form
   3,907.98/5,393.00 = 2,139.57/x
3. Step 3: Cross multiply
   3,907.98x = 5,393.00 × 2,139.57
4. Step 4: Simplify right side
   3,907.98x = 11,538,690.31
5. Step 5: Solve for x
   x = 11,538,690.31/3,907.98
6. Step 6: Final answer
   x = 2,952.60