Finding the Fourth Proportional to 1,241.69, 1,862.71 and 419.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,241.69 : 1,862.71 = 419.78 : x
2. Step 2: Convert to fraction form
   1,241.69/1,862.71 = 419.78/x
3. Step 3: Cross multiply
   1,241.69x = 1,862.71 × 419.78
4. Step 4: Simplify right side
   1,241.69x = 781,932.01
5. Step 5: Solve for x
   x = 781,932.01/1,241.69
6. Step 6: Final answer
   x = 629.73