Finding the Fourth Proportional to 1,378.50, 1,902.33 and 789.23

Step by Step Solution

1. Step 1: Write the proportion equation
   1,378.50 : 1,902.33 = 789.23 : x
2. Step 2: Convert to fraction form
   1,378.50/1,902.33 = 789.23/x
3. Step 3: Cross multiply
   1,378.50x = 1,902.33 × 789.23
4. Step 4: Simplify right side
   1,378.50x = 1,501,366.39
5. Step 5: Solve for x
   x = 1,501,366.39/1,378.50
6. Step 6: Final answer
   x = 1,089.13