Finding the Fourth Proportional to 3,920.72, 5,406.98 and 2,663.65

Step by Step Solution

1. Step 1: Write the proportion equation
   3,920.72 : 5,406.98 = 2,663.65 : x
2. Step 2: Convert to fraction form
   3,920.72/5,406.98 = 2,663.65/x
3. Step 3: Cross multiply
   3,920.72x = 5,406.98 × 2,663.65
4. Step 4: Simplify right side
   3,920.72x = 14,402,295.72
5. Step 5: Solve for x
   x = 14,402,295.72/3,920.72
6. Step 6: Final answer
   x = 3,673.39