Finding the Fourth Proportional to 2,131.53, 3,198.20 and 1,205.70

Step by Step Solution

1. Step 1: Write the proportion equation
   2,131.53 : 3,198.20 = 1,205.70 : x
2. Step 2: Convert to fraction form
   2,131.53/3,198.20 = 1,205.70/x
3. Step 3: Cross multiply
   2,131.53x = 3,198.20 × 1,205.70
4. Step 4: Simplify right side
   2,131.53x = 3,856,063.71
5. Step 5: Solve for x
   x = 3,856,063.71/2,131.53
6. Step 6: Final answer
   x = 1,809.06