Finding the Fourth Proportional to 1,687.65, 2,527.02 and 1,320.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,687.65 : 2,527.02 = 1,320.72 : x
2. Step 2: Convert to fraction form
   1,687.65/2,527.02 = 1,320.72/x
3. Step 3: Cross multiply
   1,687.65x = 2,527.02 × 1,320.72
4. Step 4: Simplify right side
   1,687.65x = 3,337,485.85
5. Step 5: Solve for x
   x = 3,337,485.85/1,687.65
6. Step 6: Final answer
   x = 1,977.59