Finding the Fourth Proportional to 1,379.18, 1,903.25 and 789.71

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.18 : 1,903.25 = 789.71 : x
2. Step 2: Convert to fraction form
   1,379.18/1,903.25 = 789.71/x
3. Step 3: Cross multiply
   1,379.18x = 1,903.25 × 789.71
4. Step 4: Simplify right side
   1,379.18x = 1,503,002.09
5. Step 5: Solve for x
   x = 1,503,002.09/1,379.18
6. Step 6: Final answer
   x = 1,089.78