Finding the Fourth Proportional to 2,782.69, 4,171.25 and 1,391.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,782.69 : 4,171.25 = 1,391.78 : x
2. Step 2: Convert to fraction form
   2,782.69/4,171.25 = 1,391.78/x
3. Step 3: Cross multiply
   2,782.69x = 4,171.25 × 1,391.78
4. Step 4: Simplify right side
   2,782.69x = 5,805,441.47
5. Step 5: Solve for x
   x = 5,805,441.47/2,782.69
6. Step 6: Final answer
   x = 2,086.27