Finding the Fourth Proportional to 1,112.56, 1,669.34 and 419.58

Step by Step Solution

1. Step 1: Write the proportion equation
   1,112.56 : 1,669.34 = 419.58 : x
2. Step 2: Convert to fraction form
   1,112.56/1,669.34 = 419.58/x
3. Step 3: Cross multiply
   1,112.56x = 1,669.34 × 419.58
4. Step 4: Simplify right side
   1,112.56x = 700,422.73
5. Step 5: Solve for x
   x = 700,422.73/1,112.56
6. Step 6: Final answer
   x = 629.56