Finding the Fourth Proportional to 1,378.39, 1,902.18 and 788.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,378.39 : 1,902.18 = 788.89 : x
2. Step 2: Convert to fraction form
   1,378.39/1,902.18 = 788.89/x
3. Step 3: Cross multiply
   1,378.39x = 1,902.18 × 788.89
4. Step 4: Simplify right side
   1,378.39x = 1,500,610.78
5. Step 5: Solve for x
   x = 1,500,610.78/1,378.39
6. Step 6: Final answer
   x = 1,088.67