Finding the Fourth Proportional to 2,286.65, 3,155.60 and 1,238.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,286.65 : 3,155.60 = 1,238.72 : x
2. Step 2: Convert to fraction form
   2,286.65/3,155.60 = 1,238.72/x
3. Step 3: Cross multiply
   2,286.65x = 3,155.60 × 1,238.72
4. Step 4: Simplify right side
   2,286.65x = 3,908,882.86
5. Step 5: Solve for x
   x = 3,908,882.86/2,286.65
6. Step 6: Final answer
   x = 1,709.43