Finding the Fourth Proportional to 6,820.72, 10,221.60 and 3,113.68

Step by Step Solution

1. Step 1: Write the proportion equation
   6,820.72 : 10,221.60 = 3,113.68 : x
2. Step 2: Convert to fraction form
   6,820.72/10,221.60 = 3,113.68/x
3. Step 3: Cross multiply
   6,820.72x = 10,221.60 × 3,113.68
4. Step 4: Simplify right side
   6,820.72x = 31,826,791.49
5. Step 5: Solve for x
   x = 31,826,791.49/6,820.72
6. Step 6: Final answer
   x = 4,666.19