Finding the Fourth Proportional to 1,447.40, 1,996.80 and 857.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,447.40 : 1,996.80 = 857.72 : x
2. Step 2: Convert to fraction form
   1,447.40/1,996.80 = 857.72/x
3. Step 3: Cross multiply
   1,447.40x = 1,996.80 × 857.72
4. Step 4: Simplify right side
   1,447.40x = 1,712,695.30
5. Step 5: Solve for x
   x = 1,712,695.30/1,447.40
6. Step 6: Final answer
   x = 1,183.29