Finding the Fourth Proportional to 2,286.72, 3,155.69 and 1,238.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,286.72 : 3,155.69 = 1,238.78 : x
2. Step 2: Convert to fraction form
   2,286.72/3,155.69 = 1,238.78/x
3. Step 3: Cross multiply
   2,286.72x = 3,155.69 × 1,238.78
4. Step 4: Simplify right side
   2,286.72x = 3,909,216.64
5. Step 5: Solve for x
   x = 3,909,216.64/2,286.72
6. Step 6: Final answer
   x = 1,709.53