Finding the Fourth Proportional to 1,419.15, 1,958.55 and 789.90

Step by Step Solution

1. Step 1: Write the proportion equation
   1,419.15 : 1,958.55 = 789.90 : x
2. Step 2: Convert to fraction form
   1,419.15/1,958.55 = 789.90/x
3. Step 3: Cross multiply
   1,419.15x = 1,958.55 × 789.90
4. Step 4: Simplify right side
   1,419.15x = 1,547,058.65
5. Step 5: Solve for x
   x = 1,547,058.65/1,419.15
6. Step 6: Final answer
   x = 1,090.13