Finding the Fourth Proportional to 3,987.31, 5,502.38 and 2,218.88

Step by Step Solution

1. Step 1: Write the proportion equation
   3,987.31 : 5,502.38 = 2,218.88 : x
2. Step 2: Convert to fraction form
   3,987.31/5,502.38 = 2,218.88/x
3. Step 3: Cross multiply
   3,987.31x = 5,502.38 × 2,218.88
4. Step 4: Simplify right side
   3,987.31x = 12,209,105.13
5. Step 5: Solve for x
   x = 12,209,105.13/3,987.31
6. Step 6: Final answer
   x = 3,061.99