Finding the Fourth Proportional to 1,802.80, 2,488.35 and 1,139.86

Step by Step Solution

1. Step 1: Write the proportion equation
   1,802.80 : 2,488.35 = 1,139.86 : x
2. Step 2: Convert to fraction form
   1,802.80/2,488.35 = 1,139.86/x
3. Step 3: Cross multiply
   1,802.80x = 2,488.35 × 1,139.86
4. Step 4: Simplify right side
   1,802.80x = 2,836,370.63
5. Step 5: Solve for x
   x = 2,836,370.63/1,802.80
6. Step 6: Final answer
   x = 1,573.31