Finding the Fourth Proportional to 1,378.66, 1,902.51 and 789.14

Step by Step Solution

1. Step 1: Write the proportion equation
   1,378.66 : 1,902.51 = 789.14 : x
2. Step 2: Convert to fraction form
   1,378.66/1,902.51 = 789.14/x
3. Step 3: Cross multiply
   1,378.66x = 1,902.51 × 789.14
4. Step 4: Simplify right side
   1,378.66x = 1,501,346.74
5. Step 5: Solve for x
   x = 1,501,346.74/1,378.66
6. Step 6: Final answer
   x = 1,088.99