Finding the Fourth Proportional to 2,520.63, 3,780.81 and 789.21

Step by Step Solution

1. Step 1: Write the proportion equation
   2,520.63 : 3,780.81 = 789.21 : x
2. Step 2: Convert to fraction form
   2,520.63/3,780.81 = 789.21/x
3. Step 3: Cross multiply
   2,520.63x = 3,780.81 × 789.21
4. Step 4: Simplify right side
   2,520.63x = 2,983,853.06
5. Step 5: Solve for x
   x = 2,983,853.06/2,520.63
6. Step 6: Final answer
   x = 1,183.77