Finding the Fourth Proportional to 1,550.85, 2,139.33 and 920.76

Step by Step Solution

1. Step 1: Write the proportion equation
   1,550.85 : 2,139.33 = 920.76 : x
2. Step 2: Convert to fraction form
   1,550.85/2,139.33 = 920.76/x
3. Step 3: Cross multiply
   1,550.85x = 2,139.33 × 920.76
4. Step 4: Simplify right side
   1,550.85x = 1,969,809.49
5. Step 5: Solve for x
   x = 1,969,809.49/1,550.85
6. Step 6: Final answer
   x = 1,270.15