Finding the Fourth Proportional to 1,687.98, 2,528.43 and 1,071.37

Step by Step Solution

1. Step 1: Write the proportion equation
   1,687.98 : 2,528.43 = 1,071.37 : x
2. Step 2: Convert to fraction form
   1,687.98/2,528.43 = 1,071.37/x
3. Step 3: Cross multiply
   1,687.98x = 2,528.43 × 1,071.37
4. Step 4: Simplify right side
   1,687.98x = 2,708,884.05
5. Step 5: Solve for x
   x = 2,708,884.05/1,687.98
6. Step 6: Final answer
   x = 1,604.81