Finding the Fourth Proportional to 1,393.44, 2,086.04 and 871.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,393.44 : 2,086.04 = 871.72 : x
2. Step 2: Convert to fraction form
   1,393.44/2,086.04 = 871.72/x
3. Step 3: Cross multiply
   1,393.44x = 2,086.04 × 871.72
4. Step 4: Simplify right side
   1,393.44x = 1,818,442.79
5. Step 5: Solve for x
   x = 1,818,442.79/1,393.44
6. Step 6: Final answer
   x = 1,305.00