Finding the Fourth Proportional to 2,131.42, 2,940.90 and 1,222.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,131.42 : 2,940.90 = 1,222.72 : x
2. Step 2: Convert to fraction form
   2,131.42/2,940.90 = 1,222.72/x
3. Step 3: Cross multiply
   2,131.42x = 2,940.90 × 1,222.72
4. Step 4: Simplify right side
   2,131.42x = 3,595,897.25
5. Step 5: Solve for x
   x = 3,595,897.25/2,131.42
6. Step 6: Final answer
   x = 1,687.09