Finding the Fourth Proportional to 1,379.03, 1,903.07 and 789.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.03 : 1,903.07 = 789.57 : x
2. Step 2: Convert to fraction form
   1,379.03/1,903.07 = 789.57/x
3. Step 3: Cross multiply
   1,379.03x = 1,903.07 × 789.57
4. Step 4: Simplify right side
   1,379.03x = 1,502,605.41
5. Step 5: Solve for x
   x = 1,502,605.41/1,379.03
6. Step 6: Final answer
   x = 1,089.61