Finding the Fourth Proportional to 2,777.87, 4,164.83 and 1,390.21

Step by Step Solution

1. Step 1: Write the proportion equation
   2,777.87 : 4,164.83 = 1,390.21 : x
2. Step 2: Convert to fraction form
   2,777.87/4,164.83 = 1,390.21/x
3. Step 3: Cross multiply
   2,777.87x = 4,164.83 × 1,390.21
4. Step 4: Simplify right side
   2,777.87x = 5,789,983.98
5. Step 5: Solve for x
   x = 5,789,983.98/2,777.87
6. Step 6: Final answer
   x = 2,084.33