Finding the Fourth Proportional to 1,105.80, 1,659.46 and 413.02

Step by Step Solution

1. Step 1: Write the proportion equation
   1,105.80 : 1,659.46 = 413.02 : x
2. Step 2: Convert to fraction form
   1,105.80/1,659.46 = 413.02/x
3. Step 3: Cross multiply
   1,105.80x = 1,659.46 × 413.02
4. Step 4: Simplify right side
   1,105.80x = 685,390.17
5. Step 5: Solve for x
   x = 685,390.17/1,105.80
6. Step 6: Final answer
   x = 619.81