Finding the Fourth Proportional to 1,379.07, 1,903.03 and 789.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.07 : 1,903.03 = 789.80 : x
2. Step 2: Convert to fraction form
   1,379.07/1,903.03 = 789.80/x
3. Step 3: Cross multiply
   1,379.07x = 1,903.03 × 789.80
4. Step 4: Simplify right side
   1,379.07x = 1,503,001.60
5. Step 5: Solve for x
   x = 1,503,001.60/1,379.07
6. Step 6: Final answer
   x = 1,089.87