Finding the Fourth Proportional to 1,378.86, 1,902.83 and 789.38

Step by Step Solution

1. Step 1: Write the proportion equation
   1,378.86 : 1,902.83 = 789.38 : x
2. Step 2: Convert to fraction form
   1,378.86/1,902.83 = 789.38/x
3. Step 3: Cross multiply
   1,378.86x = 1,902.83 × 789.38
4. Step 4: Simplify right side
   1,378.86x = 1,502,049.62
5. Step 5: Solve for x
   x = 1,502,049.62/1,378.86
6. Step 6: Final answer
   x = 1,089.34