Finding the Fourth Proportional to 1,238.93, 1,709.78 and 679.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,238.93 : 1,709.78 = 679.42 : x
2. Step 2: Convert to fraction form
   1,238.93/1,709.78 = 679.42/x
3. Step 3: Cross multiply
   1,238.93x = 1,709.78 × 679.42
4. Step 4: Simplify right side
   1,238.93x = 1,161,659.33
5. Step 5: Solve for x
   x = 1,161,659.33/1,238.93
6. Step 6: Final answer
   x = 937.63