Finding the Fourth Proportional to 2,211.34, 3,318.38 and 1,287.31

Step by Step Solution

1. Step 1: Write the proportion equation
   2,211.34 : 3,318.38 = 1,287.31 : x
2. Step 2: Convert to fraction form
   2,211.34/3,318.38 = 1,287.31/x
3. Step 3: Cross multiply
   2,211.34x = 3,318.38 × 1,287.31
4. Step 4: Simplify right side
   2,211.34x = 4,271,760.73
5. Step 5: Solve for x
   x = 4,271,760.73/2,211.34
6. Step 6: Final answer
   x = 1,931.76