Finding the Fourth Proportional to 2,670.87, 4,002.85 and 1,281.31

Step by Step Solution

1. Step 1: Write the proportion equation
   2,670.87 : 4,002.85 = 1,281.31 : x
2. Step 2: Convert to fraction form
   2,670.87/4,002.85 = 1,281.31/x
3. Step 3: Cross multiply
   2,670.87x = 4,002.85 × 1,281.31
4. Step 4: Simplify right side
   2,670.87x = 5,128,891.73
5. Step 5: Solve for x
   x = 5,128,891.73/2,670.87
6. Step 6: Final answer
   x = 1,920.31