Finding the Fourth Proportional to 1,709.11, 2,358.69 and 1,288.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,709.11 : 2,358.69 = 1,288.72 : x
2. Step 2: Convert to fraction form
   1,709.11/2,358.69 = 1,288.72/x
3. Step 3: Cross multiply
   1,709.11x = 2,358.69 × 1,288.72
4. Step 4: Simplify right side
   1,709.11x = 3,039,690.98
5. Step 5: Solve for x
   x = 3,039,690.98/1,709.11
6. Step 6: Final answer
   x = 1,778.52