Finding the Fourth Proportional to 3,928.71, 5,419.80 and 2,511.72

Step by Step Solution

1. Step 1: Write the proportion equation
   3,928.71 : 5,419.80 = 2,511.72 : x
2. Step 2: Convert to fraction form
   3,928.71/5,419.80 = 2,511.72/x
3. Step 3: Cross multiply
   3,928.71x = 5,419.80 × 2,511.72
4. Step 4: Simplify right side
   3,928.71x = 13,613,020.06
5. Step 5: Solve for x
   x = 13,613,020.06/3,928.71
6. Step 6: Final answer
   x = 3,465.01