Finding the Fourth Proportional to 1,659.40, 2,485.56 and 1,311.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,659.40 : 2,485.56 = 1,311.10 : x
2. Step 2: Convert to fraction form
   1,659.40/2,485.56 = 1,311.10/x
3. Step 3: Cross multiply
   1,659.40x = 2,485.56 × 1,311.10
4. Step 4: Simplify right side
   1,659.40x = 3,258,817.72
5. Step 5: Solve for x
   x = 3,258,817.72/1,659.40
6. Step 6: Final answer
   x = 1,963.85