Finding the Fourth Proportional to 1,380.49, 1,903.02 and 1,007.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.49 : 1,903.02 = 1,007.89 : x
2. Step 2: Convert to fraction form
   1,380.49/1,903.02 = 1,007.89/x
3. Step 3: Cross multiply
   1,380.49x = 1,903.02 × 1,007.89
4. Step 4: Simplify right side
   1,380.49x = 1,918,034.83
5. Step 5: Solve for x
   x = 1,918,034.83/1,380.49
6. Step 6: Final answer
   x = 1,389.39