Finding the Fourth Proportional to 2,144.91, 3,215.60 and 912.16

Step by Step Solution

1. Step 1: Write the proportion equation
   2,144.91 : 3,215.60 = 912.16 : x
2. Step 2: Convert to fraction form
   2,144.91/3,215.60 = 912.16/x
3. Step 3: Cross multiply
   2,144.91x = 3,215.60 × 912.16
4. Step 4: Simplify right side
   2,144.91x = 2,933,144.58
5. Step 5: Solve for x
   x = 2,933,144.58/2,144.91
6. Step 6: Final answer
   x = 1,367.49