Finding the Fourth Proportional to 2,231.82, 3,079.86 and 1,287.55

Step by Step Solution

1. Step 1: Write the proportion equation
   2,231.82 : 3,079.86 = 1,287.55 : x
2. Step 2: Convert to fraction form
   2,231.82/3,079.86 = 1,287.55/x
3. Step 3: Cross multiply
   2,231.82x = 3,079.86 × 1,287.55
4. Step 4: Simplify right side
   2,231.82x = 3,965,458.34
5. Step 5: Solve for x
   x = 3,965,458.34/2,231.82
6. Step 6: Final answer
   x = 1,776.79