Finding the Fourth Proportional to 1,290.72, 1,935.89 and 413.33

Step by Step Solution

1. Step 1: Write the proportion equation
   1,290.72 : 1,935.89 = 413.33 : x
2. Step 2: Convert to fraction form
   1,290.72/1,935.89 = 413.33/x
3. Step 3: Cross multiply
   1,290.72x = 1,935.89 × 413.33
4. Step 4: Simplify right side
   1,290.72x = 800,149.67
5. Step 5: Solve for x
   x = 800,149.67/1,290.72
6. Step 6: Final answer
   x = 619.93