Finding the Fourth Proportional to 2,560.21, 3,836.59 and 1,389.22

Step by Step Solution

1. Step 1: Write the proportion equation
   2,560.21 : 3,836.59 = 1,389.22 : x
2. Step 2: Convert to fraction form
   2,560.21/3,836.59 = 1,389.22/x
3. Step 3: Cross multiply
   2,560.21x = 3,836.59 × 1,389.22
4. Step 4: Simplify right side
   2,560.21x = 5,329,867.56
5. Step 5: Solve for x
   x = 5,329,867.56/2,560.21
6. Step 6: Final answer
   x = 2,081.81