Finding the Fourth Proportional to 1,238.87, 1,709.61 and 679.34

Step by Step Solution

1. Step 1: Write the proportion equation
   1,238.87 : 1,709.61 = 679.34 : x
2. Step 2: Convert to fraction form
   1,238.87/1,709.61 = 679.34/x
3. Step 3: Cross multiply
   1,238.87x = 1,709.61 × 679.34
4. Step 4: Simplify right side
   1,238.87x = 1,161,406.46
5. Step 5: Solve for x
   x = 1,161,406.46/1,238.87
6. Step 6: Final answer
   x = 937.47