Finding the Fourth Proportional to 2,142.24, 3,212.78 and 826.16

Step by Step Solution

1. Step 1: Write the proportion equation
   2,142.24 : 3,212.78 = 826.16 : x
2. Step 2: Convert to fraction form
   2,142.24/3,212.78 = 826.16/x
3. Step 3: Cross multiply
   2,142.24x = 3,212.78 × 826.16
4. Step 4: Simplify right side
   2,142.24x = 2,654,272.85
5. Step 5: Solve for x
   x = 2,654,272.85/2,142.24
6. Step 6: Final answer
   x = 1,239.02