Finding the Fourth Proportional to 2,212.43, 3,317.56 and 1,288.31

Step by Step Solution

1. Step 1: Write the proportion equation
   2,212.43 : 3,317.56 = 1,288.31 : x
2. Step 2: Convert to fraction form
   2,212.43/3,317.56 = 1,288.31/x
3. Step 3: Cross multiply
   2,212.43x = 3,317.56 × 1,288.31
4. Step 4: Simplify right side
   2,212.43x = 4,274,025.92
5. Step 5: Solve for x
   x = 4,274,025.92/2,212.43
6. Step 6: Final answer
   x = 1,931.83