Finding the Fourth Proportional to 3,986.89, 5,501.91 and 2,218.50

Step by Step Solution

1. Step 1: Write the proportion equation
   3,986.89 : 5,501.91 = 2,218.50 : x
2. Step 2: Convert to fraction form
   3,986.89/5,501.91 = 2,218.50/x
3. Step 3: Cross multiply
   3,986.89x = 5,501.91 × 2,218.50
4. Step 4: Simplify right side
   3,986.89x = 12,205,987.34
5. Step 5: Solve for x
   x = 12,205,987.34/3,986.89
6. Step 6: Final answer
   x = 3,061.53