Finding the Fourth Proportional to 2,782.72, 4,173.52 and 1,139.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,782.72 : 4,173.52 = 1,139.20 : x
2. Step 2: Convert to fraction form
   2,782.72/4,173.52 = 1,139.20/x
3. Step 3: Cross multiply
   2,782.72x = 4,173.52 × 1,139.20
4. Step 4: Simplify right side
   2,782.72x = 4,754,473.98
5. Step 5: Solve for x
   x = 4,754,473.98/2,782.72
6. Step 6: Final answer
   x = 1,708.57