Finding the Fourth Proportional to 2,131.77, 3,198.71 and 1,309.62

Step by Step Solution

1. Step 1: Write the proportion equation
   2,131.77 : 3,198.71 = 1,309.62 : x
2. Step 2: Convert to fraction form
   2,131.77/3,198.71 = 1,309.62/x
3. Step 3: Cross multiply
   2,131.77x = 3,198.71 × 1,309.62
4. Step 4: Simplify right side
   2,131.77x = 4,189,094.59
5. Step 5: Solve for x
   x = 4,189,094.59/2,131.77
6. Step 6: Final answer
   x = 1,965.08