Finding the Fourth Proportional to 1,380.89, 2,071.42 and 559.18

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.89 : 2,071.42 = 559.18 : x
2. Step 2: Convert to fraction form
   1,380.89/2,071.42 = 559.18/x
3. Step 3: Cross multiply
   1,380.89x = 2,071.42 × 559.18
4. Step 4: Simplify right side
   1,380.89x = 1,158,286.18
5. Step 5: Solve for x
   x = 1,158,286.18/1,380.89
6. Step 6: Final answer
   x = 838.80