Finding the Fourth Proportional to 1,380.99, 1,903.71 and 1,008.39

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.99 : 1,903.71 = 1,008.39 : x
2. Step 2: Convert to fraction form
   1,380.99/1,903.71 = 1,008.39/x
3. Step 3: Cross multiply
   1,380.99x = 1,903.71 × 1,008.39
4. Step 4: Simplify right side
   1,380.99x = 1,919,682.13
5. Step 5: Solve for x
   x = 1,919,682.13/1,380.99
6. Step 6: Final answer
   x = 1,390.08