Finding the Fourth Proportional to 1,418.67, 1,957.71 and 789.21

Step by Step Solution

1. Step 1: Write the proportion equation
   1,418.67 : 1,957.71 = 789.21 : x
2. Step 2: Convert to fraction form
   1,418.67/1,957.71 = 789.21/x
3. Step 3: Cross multiply
   1,418.67x = 1,957.71 × 789.21
4. Step 4: Simplify right side
   1,418.67x = 1,545,044.31
5. Step 5: Solve for x
   x = 1,545,044.31/1,418.67
6. Step 6: Final answer
   x = 1,089.08