Finding the Fourth Proportional to 1,311.41, 1,808.37 and 979.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,311.41 : 1,808.37 = 979.31 : x
2. Step 2: Convert to fraction form
   1,311.41/1,808.37 = 979.31/x
3. Step 3: Cross multiply
   1,311.41x = 1,808.37 × 979.31
4. Step 4: Simplify right side
   1,311.41x = 1,770,954.82
5. Step 5: Solve for x
   x = 1,770,954.82/1,311.41
6. Step 6: Final answer
   x = 1,350.42