Finding the Fourth Proportional to 1,379.40, 1,903.36 and 789.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.40 : 1,903.36 = 789.82 : x
2. Step 2: Convert to fraction form
   1,379.40/1,903.36 = 789.82/x
3. Step 3: Cross multiply
   1,379.40x = 1,903.36 × 789.82
4. Step 4: Simplify right side
   1,379.40x = 1,503,309.67
5. Step 5: Solve for x
   x = 1,503,309.67/1,379.40
6. Step 6: Final answer
   x = 1,089.83