Finding the Fourth Proportional to 2,131.94, 2,942.09 and 1,187.80

Step by Step Solution

1. Step 1: Write the proportion equation
   2,131.94 : 2,942.09 = 1,187.80 : x
2. Step 2: Convert to fraction form
   2,131.94/2,942.09 = 1,187.80/x
3. Step 3: Cross multiply
   2,131.94x = 2,942.09 × 1,187.80
4. Step 4: Simplify right side
   2,131.94x = 3,494,614.50
5. Step 5: Solve for x
   x = 3,494,614.50/2,131.94
6. Step 6: Final answer
   x = 1,639.17