Finding the Fourth Proportional to 2,131.83, 3,198.87 and 816.48

Step by Step Solution

1. Step 1: Write the proportion equation
   2,131.83 : 3,198.87 = 816.48 : x
2. Step 2: Convert to fraction form
   2,131.83/3,198.87 = 816.48/x
3. Step 3: Cross multiply
   2,131.83x = 3,198.87 × 816.48
4. Step 4: Simplify right side
   2,131.83x = 2,611,813.38
5. Step 5: Solve for x
   x = 2,611,813.38/2,131.83
6. Step 6: Final answer
   x = 1,225.15