Finding the Fourth Proportional to 2,356.12, 3,531.87 and 1,123.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,356.12 : 3,531.87 = 1,123.20 : x
2. Step 2: Convert to fraction form
   2,356.12/3,531.87 = 1,123.20/x
3. Step 3: Cross multiply
   2,356.12x = 3,531.87 × 1,123.20
4. Step 4: Simplify right side
   2,356.12x = 3,966,996.38
5. Step 5: Solve for x
   x = 3,966,996.38/2,356.12
6. Step 6: Final answer
   x = 1,683.70