Finding the Fourth Proportional to 1,423.20, 2,123.46 and 1,215.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,423.20 : 2,123.46 = 1,215.48 : x
2. Step 2: Convert to fraction form
   1,423.20/2,123.46 = 1,215.48/x
3. Step 3: Cross multiply
   1,423.20x = 2,123.46 × 1,215.48
4. Step 4: Simplify right side
   1,423.20x = 2,581,023.16
5. Step 5: Solve for x
   x = 2,581,023.16/1,423.20
6. Step 6: Final answer
   x = 1,813.54