Finding the Fourth Proportional to 2,131.96, 3,198.04 and 1,309.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,131.96 : 3,198.04 = 1,309.72 : x
2. Step 2: Convert to fraction form
   2,131.96/3,198.04 = 1,309.72/x
3. Step 3: Cross multiply
   2,131.96x = 3,198.04 × 1,309.72
4. Step 4: Simplify right side
   2,131.96x = 4,188,536.95
5. Step 5: Solve for x
   x = 4,188,536.95/2,131.96
6. Step 6: Final answer
   x = 1,964.64