Finding the Fourth Proportional to 2,690.34, 4,028.22 and 1,389.06

Step by Step Solution

1. Step 1: Write the proportion equation
   2,690.34 : 4,028.22 = 1,389.06 : x
2. Step 2: Convert to fraction form
   2,690.34/4,028.22 = 1,389.06/x
3. Step 3: Cross multiply
   2,690.34x = 4,028.22 × 1,389.06
4. Step 4: Simplify right side
   2,690.34x = 5,595,439.27
5. Step 5: Solve for x
   x = 5,595,439.27/2,690.34
6. Step 6: Final answer
   x = 2,079.83