Finding the Fourth Proportional to 1,379.22, 1,902.89 and 789.65

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.22 : 1,902.89 = 789.65 : x
2. Step 2: Convert to fraction form
   1,379.22/1,902.89 = 789.65/x
3. Step 3: Cross multiply
   1,379.22x = 1,902.89 × 789.65
4. Step 4: Simplify right side
   1,379.22x = 1,502,609.55
5. Step 5: Solve for x
   x = 1,502,609.55/1,379.22
6. Step 6: Final answer
   x = 1,089.46