Finding the Fourth Proportional to 2,123.42, 3,180.99 and 1,390.77

Step by Step Solution

1. Step 1: Write the proportion equation
   2,123.42 : 3,180.99 = 1,390.77 : x
2. Step 2: Convert to fraction form
   2,123.42/3,180.99 = 1,390.77/x
3. Step 3: Cross multiply
   2,123.42x = 3,180.99 × 1,390.77
4. Step 4: Simplify right side
   2,123.42x = 4,424,025.46
5. Step 5: Solve for x
   x = 4,424,025.46/2,123.42
6. Step 6: Final answer
   x = 2,083.44