Finding the Fourth Proportional to 1,387.50, 2,081.33 and 413.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,387.50 : 2,081.33 = 413.61 : x
2. Step 2: Convert to fraction form
   1,387.50/2,081.33 = 413.61/x
3. Step 3: Cross multiply
   1,387.50x = 2,081.33 × 413.61
4. Step 4: Simplify right side
   1,387.50x = 860,856.83
5. Step 5: Solve for x
   x = 860,856.83/1,387.50
6. Step 6: Final answer
   x = 620.44