Finding the Fourth Proportional to 2,143.12, 3,212.49 and 1,216.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,143.12 : 3,212.49 = 1,216.72 : x
2. Step 2: Convert to fraction form
   2,143.12/3,212.49 = 1,216.72/x
3. Step 3: Cross multiply
   2,143.12x = 3,212.49 × 1,216.72
4. Step 4: Simplify right side
   2,143.12x = 3,908,699.15
5. Step 5: Solve for x
   x = 3,908,699.15/2,143.12
6. Step 6: Final answer
   x = 1,823.84