Finding the Fourth Proportional to 1,665.81, 2,500.20 and 789.39

Step by Step Solution

1. Step 1: Write the proportion equation
   1,665.81 : 2,500.20 = 789.39 : x
2. Step 2: Convert to fraction form
   1,665.81/2,500.20 = 789.39/x
3. Step 3: Cross multiply
   1,665.81x = 2,500.20 × 789.39
4. Step 4: Simplify right side
   1,665.81x = 1,973,632.88
5. Step 5: Solve for x
   x = 1,973,632.88/1,665.81
6. Step 6: Final answer
   x = 1,184.79