Finding the Fourth Proportional to 1,447.20, 1,996.88 and 857.76

Step by Step Solution

1. Step 1: Write the proportion equation
   1,447.20 : 1,996.88 = 857.76 : x
2. Step 2: Convert to fraction form
   1,447.20/1,996.88 = 857.76/x
3. Step 3: Cross multiply
   1,447.20x = 1,996.88 × 857.76
4. Step 4: Simplify right side
   1,447.20x = 1,712,843.79
5. Step 5: Solve for x
   x = 1,712,843.79/1,447.20
6. Step 6: Final answer
   x = 1,183.56