Finding the Fourth Proportional to 2,287.49, 3,156.79 and 1,390.92

Step by Step Solution

1. Step 1: Write the proportion equation
   2,287.49 : 3,156.79 = 1,390.92 : x
2. Step 2: Convert to fraction form
   2,287.49/3,156.79 = 1,390.92/x
3. Step 3: Cross multiply
   2,287.49x = 3,156.79 × 1,390.92
4. Step 4: Simplify right side
   2,287.49x = 4,390,842.35
5. Step 5: Solve for x
   x = 4,390,842.35/2,287.49
6. Step 6: Final answer
   x = 1,919.50