Finding the Fourth Proportional to 5,708.72, 7,874.64 and 3,609.20

Step by Step Solution

1. Step 1: Write the proportion equation
   5,708.72 : 7,874.64 = 3,609.20 : x
2. Step 2: Convert to fraction form
   5,708.72/7,874.64 = 3,609.20/x
3. Step 3: Cross multiply
   5,708.72x = 7,874.64 × 3,609.20
4. Step 4: Simplify right side
   5,708.72x = 28,421,150.69
5. Step 5: Solve for x
   x = 28,421,150.69/5,708.72
6. Step 6: Final answer
   x = 4,978.55