Finding the Fourth Proportional to 3,920.04, 5,409.82 and 2,151.72

Step by Step Solution

1. Step 1: Write the proportion equation
   3,920.04 : 5,409.82 = 2,151.72 : x
2. Step 2: Convert to fraction form
   3,920.04/5,409.82 = 2,151.72/x
3. Step 3: Cross multiply
   3,920.04x = 5,409.82 × 2,151.72
4. Step 4: Simplify right side
   3,920.04x = 11,640,417.89
5. Step 5: Solve for x
   x = 11,640,417.89/3,920.04
6. Step 6: Final answer
   x = 2,969.46