Finding the Fourth Proportional to 2,082.56, 3,123.90 and 928.40

Step by Step Solution

1. Step 1: Write the proportion equation
   2,082.56 : 3,123.90 = 928.40 : x
2. Step 2: Convert to fraction form
   2,082.56/3,123.90 = 928.40/x
3. Step 3: Cross multiply
   2,082.56x = 3,123.90 × 928.40
4. Step 4: Simplify right side
   2,082.56x = 2,900,228.76
5. Step 5: Solve for x
   x = 2,900,228.76/2,082.56
6. Step 6: Final answer
   x = 1,392.63