Finding the Fourth Proportional to 1,391.61, 1,920.75 and 949.71

Step by Step Solution

1. Step 1: Write the proportion equation
   1,391.61 : 1,920.75 = 949.71 : x
2. Step 2: Convert to fraction form
   1,391.61/1,920.75 = 949.71/x
3. Step 3: Cross multiply
   1,391.61x = 1,920.75 × 949.71
4. Step 4: Simplify right side
   1,391.61x = 1,824,155.48
5. Step 5: Solve for x
   x = 1,824,155.48/1,391.61
6. Step 6: Final answer
   x = 1,310.82