Finding the Fourth Proportional to 2,112.80, 3,168.96 and 814.16

Step by Step Solution

1. Step 1: Write the proportion equation
   2,112.80 : 3,168.96 = 814.16 : x
2. Step 2: Convert to fraction form
   2,112.80/3,168.96 = 814.16/x
3. Step 3: Cross multiply
   2,112.80x = 3,168.96 × 814.16
4. Step 4: Simplify right side
   2,112.80x = 2,580,040.47
5. Step 5: Solve for x
   x = 2,580,040.47/2,112.80
6. Step 6: Final answer
   x = 1,221.15