Finding the Fourth Proportional to 2,112.66, 3,169.89 and 813.82

Step by Step Solution

1. Step 1: Write the proportion equation
   2,112.66 : 3,169.89 = 813.82 : x
2. Step 2: Convert to fraction form
   2,112.66/3,169.89 = 813.82/x
3. Step 3: Cross multiply
   2,112.66x = 3,169.89 × 813.82
4. Step 4: Simplify right side
   2,112.66x = 2,579,719.88
5. Step 5: Solve for x
   x = 2,579,719.88/2,112.66
6. Step 6: Final answer
   x = 1,221.08