Finding the Fourth Proportional to 1,378.30, 1,902.18 and 789.07

Step by Step Solution

1. Step 1: Write the proportion equation
   1,378.30 : 1,902.18 = 789.07 : x
2. Step 2: Convert to fraction form
   1,378.30/1,902.18 = 789.07/x
3. Step 3: Cross multiply
   1,378.30x = 1,902.18 × 789.07
4. Step 4: Simplify right side
   1,378.30x = 1,500,953.17
5. Step 5: Solve for x
   x = 1,500,953.17/1,378.30
6. Step 6: Final answer
   x = 1,088.99