Finding the Fourth Proportional to 1,379.24, 1,903.30 and 789.74

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.24 : 1,903.30 = 789.74 : x
2. Step 2: Convert to fraction form
   1,379.24/1,903.30 = 789.74/x
3. Step 3: Cross multiply
   1,379.24x = 1,903.30 × 789.74
4. Step 4: Simplify right side
   1,379.24x = 1,503,100.65
5. Step 5: Solve for x
   x = 1,503,100.65/1,379.24
6. Step 6: Final answer
   x = 1,089.81