Finding the Fourth Proportional to 3,744.20, 5,612.25 and 1,987.31

Step by Step Solution

1. Step 1: Write the proportion equation
   3,744.20 : 5,612.25 = 1,987.31 : x
2. Step 2: Convert to fraction form
   3,744.20/5,612.25 = 1,987.31/x
3. Step 3: Cross multiply
   3,744.20x = 5,612.25 × 1,987.31
4. Step 4: Simplify right side
   3,744.20x = 11,153,280.55
5. Step 5: Solve for x
   x = 11,153,280.55/3,744.20
6. Step 6: Final answer
   x = 2,978.82