Finding the Fourth Proportional to 2,216.32, 3,321.30 and 1,720.40

Step by Step Solution

1. Step 1: Write the proportion equation
   2,216.32 : 3,321.30 = 1,720.40 : x
2. Step 2: Convert to fraction form
   2,216.32/3,321.30 = 1,720.40/x
3. Step 3: Cross multiply
   2,216.32x = 3,321.30 × 1,720.40
4. Step 4: Simplify right side
   2,216.32x = 5,713,964.52
5. Step 5: Solve for x
   x = 5,713,964.52/2,216.32
6. Step 6: Final answer
   x = 2,578.13