Finding the Fourth Proportional to 3,990.72, 5,506.56 and 2,418.88

Step by Step Solution

1. Step 1: Write the proportion equation
   3,990.72 : 5,506.56 = 2,418.88 : x
2. Step 2: Convert to fraction form
   3,990.72/5,506.56 = 2,418.88/x
3. Step 3: Cross multiply
   3,990.72x = 5,506.56 × 2,418.88
4. Step 4: Simplify right side
   3,990.72x = 13,319,707.85
5. Step 5: Solve for x
   x = 13,319,707.85/3,990.72
6. Step 6: Final answer
   x = 3,337.67