Finding the Fourth Proportional to 1,279.72, 1,919.16 and 413.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,279.72 : 1,919.16 = 413.82 : x
2. Step 2: Convert to fraction form
   1,279.72/1,919.16 = 413.82/x
3. Step 3: Cross multiply
   1,279.72x = 1,919.16 × 413.82
4. Step 4: Simplify right side
   1,279.72x = 794,186.79
5. Step 5: Solve for x
   x = 794,186.79/1,279.72
6. Step 6: Final answer
   x = 620.59