Finding the Fourth Proportional to 1,855.98, 2,559.15 and 1,389.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,855.98 : 2,559.15 = 1,389.42 : x
2. Step 2: Convert to fraction form
   1,855.98/2,559.15 = 1,389.42/x
3. Step 3: Cross multiply
   1,855.98x = 2,559.15 × 1,389.42
4. Step 4: Simplify right side
   1,855.98x = 3,555,734.19
5. Step 5: Solve for x
   x = 3,555,734.19/1,855.98
6. Step 6: Final answer
   x = 1,915.83