Finding the Fourth Proportional to 1,271.79, 1,906.83 and 613.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,271.79 : 1,906.83 = 613.31 : x
2. Step 2: Convert to fraction form
   1,271.79/1,906.83 = 613.31/x
3. Step 3: Cross multiply
   1,271.79x = 1,906.83 × 613.31
4. Step 4: Simplify right side
   1,271.79x = 1,169,468.37
5. Step 5: Solve for x
   x = 1,169,468.37/1,271.79
6. Step 6: Final answer
   x = 919.55