Finding the Fourth Proportional to 2,287.46, 3,156.78 and 1,390.94

Step by Step Solution

1. Step 1: Write the proportion equation
   2,287.46 : 3,156.78 = 1,390.94 : x
2. Step 2: Convert to fraction form
   2,287.46/3,156.78 = 1,390.94/x
3. Step 3: Cross multiply
   2,287.46x = 3,156.78 × 1,390.94
4. Step 4: Simplify right side
   2,287.46x = 4,390,904.68
5. Step 5: Solve for x
   x = 4,390,904.68/2,287.46
6. Step 6: Final answer
   x = 1,919.55