Finding the Fourth Proportional to 1,238.27, 1,857.38 and 405.45

Step by Step Solution

1. Step 1: Write the proportion equation
   1,238.27 : 1,857.38 = 405.45 : x
2. Step 2: Convert to fraction form
   1,238.27/1,857.38 = 405.45/x
3. Step 3: Cross multiply
   1,238.27x = 1,857.38 × 405.45
4. Step 4: Simplify right side
   1,238.27x = 753,072.69
5. Step 5: Solve for x
   x = 753,072.69/1,238.27
6. Step 6: Final answer
   x = 608.17