Finding the Fourth Proportional to 1,379.35, 1,903.30 and 789.77

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.35 : 1,903.30 = 789.77 : x
2. Step 2: Convert to fraction form
   1,379.35/1,903.30 = 789.77/x
3. Step 3: Cross multiply
   1,379.35x = 1,903.30 × 789.77
4. Step 4: Simplify right side
   1,379.35x = 1,503,169.24
5. Step 5: Solve for x
   x = 1,503,169.24/1,379.35
6. Step 6: Final answer
   x = 1,089.77