Finding the Fourth Proportional to 2,142.28, 3,216.60 and 1,318.18

Step by Step Solution

1. Step 1: Write the proportion equation
   2,142.28 : 3,216.60 = 1,318.18 : x
2. Step 2: Convert to fraction form
   2,142.28/3,216.60 = 1,318.18/x
3. Step 3: Cross multiply
   2,142.28x = 3,216.60 × 1,318.18
4. Step 4: Simplify right side
   2,142.28x = 4,240,057.79
5. Step 5: Solve for x
   x = 4,240,057.79/2,142.28
6. Step 6: Final answer
   x = 1,979.23