Finding the Fourth Proportional to 1,379.43, 1,903.68 and 789.95

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.43 : 1,903.68 = 789.95 : x
2. Step 2: Convert to fraction form
   1,379.43/1,903.68 = 789.95/x
3. Step 3: Cross multiply
   1,379.43x = 1,903.68 × 789.95
4. Step 4: Simplify right side
   1,379.43x = 1,503,816.78
5. Step 5: Solve for x
   x = 1,503,816.78/1,379.43
6. Step 6: Final answer
   x = 1,090.17