Finding the Fourth Proportional to 1,105.72, 1,658.59 and 412.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,105.72 : 1,658.59 = 412.57 : x
2. Step 2: Convert to fraction form
   1,105.72/1,658.59 = 412.57/x
3. Step 3: Cross multiply
   1,105.72x = 1,658.59 × 412.57
4. Step 4: Simplify right side
   1,105.72x = 684,284.48
5. Step 5: Solve for x
   x = 684,284.48/1,105.72
6. Step 6: Final answer
   x = 618.86