Finding the Fourth Proportional to 1,379.59, 1,903.38 and 789.70

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.59 : 1,903.38 = 789.70 : x
2. Step 2: Convert to fraction form
   1,379.59/1,903.38 = 789.70/x
3. Step 3: Cross multiply
   1,379.59x = 1,903.38 × 789.70
4. Step 4: Simplify right side
   1,379.59x = 1,503,099.19
5. Step 5: Solve for x
   x = 1,503,099.19/1,379.59
6. Step 6: Final answer
   x = 1,089.53