Finding the Fourth Proportional to 2,123.10, 3,186.68 and 1,661.40

Step by Step Solution

1. Step 1: Write the proportion equation
   2,123.10 : 3,186.68 = 1,661.40 : x
2. Step 2: Convert to fraction form
   2,123.10/3,186.68 = 1,661.40/x
3. Step 3: Cross multiply
   2,123.10x = 3,186.68 × 1,661.40
4. Step 4: Simplify right side
   2,123.10x = 5,294,341.85
5. Step 5: Solve for x
   x = 5,294,341.85/2,123.10
6. Step 6: Final answer
   x = 2,493.68