Finding the Fourth Proportional to 3,789.72, 5,686.20 and 2,143.80

Step by Step Solution

1. Step 1: Write the proportion equation
   3,789.72 : 5,686.20 = 2,143.80 : x
2. Step 2: Convert to fraction form
   3,789.72/5,686.20 = 2,143.80/x
3. Step 3: Cross multiply
   3,789.72x = 5,686.20 × 2,143.80
4. Step 4: Simplify right side
   3,789.72x = 12,190,075.56
5. Step 5: Solve for x
   x = 12,190,075.56/3,789.72
6. Step 6: Final answer
   x = 3,216.62