Finding the Fourth Proportional to 1,380.13, 2,058.59 and 1,255.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.13 : 2,058.59 = 1,255.57 : x
2. Step 2: Convert to fraction form
   1,380.13/2,058.59 = 1,255.57/x
3. Step 3: Cross multiply
   1,380.13x = 2,058.59 × 1,255.57
4. Step 4: Simplify right side
   1,380.13x = 2,584,700.33
5. Step 5: Solve for x
   x = 2,584,700.33/1,380.13
6. Step 6: Final answer
   x = 1,872.80