Finding the Fourth Proportional to 3,985.20, 5,499.90 and 2,216.70

Step by Step Solution

1. Step 1: Write the proportion equation
   3,985.20 : 5,499.90 = 2,216.70 : x
2. Step 2: Convert to fraction form
   3,985.20/5,499.90 = 2,216.70/x
3. Step 3: Cross multiply
   3,985.20x = 5,499.90 × 2,216.70
4. Step 4: Simplify right side
   3,985.20x = 12,191,628.33
5. Step 5: Solve for x
   x = 12,191,628.33/3,985.20
6. Step 6: Final answer
   x = 3,059.23