Finding the Fourth Proportional to 1,378.47, 1,902.34 and 789.04

Step by Step Solution

1. Step 1: Write the proportion equation
   1,378.47 : 1,902.34 = 789.04 : x
2. Step 2: Convert to fraction form
   1,378.47/1,902.34 = 789.04/x
3. Step 3: Cross multiply
   1,378.47x = 1,902.34 × 789.04
4. Step 4: Simplify right side
   1,378.47x = 1,501,021.28
5. Step 5: Solve for x
   x = 1,501,021.28/1,378.47
6. Step 6: Final answer
   x = 1,088.91