Finding the Fourth Proportional to 1,348.98, 1,861.61 and 789.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,348.98 : 1,861.61 = 789.78 : x
2. Step 2: Convert to fraction form
   1,348.98/1,861.61 = 789.78/x
3. Step 3: Cross multiply
   1,348.98x = 1,861.61 × 789.78
4. Step 4: Simplify right side
   1,348.98x = 1,470,257.34
5. Step 5: Solve for x
   x = 1,470,257.34/1,348.98
6. Step 6: Final answer
   x = 1,089.90