Finding the Fourth Proportional to 1,390.57, 1,919.85 and 949.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,390.57 : 1,919.85 = 949.83 : x
2. Step 2: Convert to fraction form
   1,390.57/1,919.85 = 949.83/x
3. Step 3: Cross multiply
   1,390.57x = 1,919.85 × 949.83
4. Step 4: Simplify right side
   1,390.57x = 1,823,525.71
5. Step 5: Solve for x
   x = 1,823,525.71/1,390.57
6. Step 6: Final answer
   x = 1,311.35