Finding the Fourth Proportional to 2,272.91, 3,407.30 and 811.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,272.91 : 3,407.30 = 811.72 : x
2. Step 2: Convert to fraction form
   2,272.91/3,407.30 = 811.72/x
3. Step 3: Cross multiply
   2,272.91x = 3,407.30 × 811.72
4. Step 4: Simplify right side
   2,272.91x = 2,765,760.98
5. Step 5: Solve for x
   x = 2,765,760.98/2,272.91
6. Step 6: Final answer
   x = 1,216.84