Finding the Fourth Proportional to 1,212.72, 1,674.04 and 820.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,212.72 : 1,674.04 = 820.88 : x
2. Step 2: Convert to fraction form
   1,212.72/1,674.04 = 820.88/x
3. Step 3: Cross multiply
   1,212.72x = 1,674.04 × 820.88
4. Step 4: Simplify right side
   1,212.72x = 1,374,185.96
5. Step 5: Solve for x
   x = 1,374,185.96/1,212.72
6. Step 6: Final answer
   x = 1,133.14