Finding the Fourth Proportional to 3,987.36, 5,501.88 and 2,218.72

Step by Step Solution

1. Step 1: Write the proportion equation
   3,987.36 : 5,501.88 = 2,218.72 : x
2. Step 2: Convert to fraction form
   3,987.36/5,501.88 = 2,218.72/x
3. Step 3: Cross multiply
   3,987.36x = 5,501.88 × 2,218.72
4. Step 4: Simplify right side
   3,987.36x = 12,207,131.19
5. Step 5: Solve for x
   x = 12,207,131.19/3,987.36
6. Step 6: Final answer
   x = 3,061.46