Finding the Fourth Proportional to 2,930.75, 4,395.90 and 1,287.31

Step by Step Solution

1. Step 1: Write the proportion equation
   2,930.75 : 4,395.90 = 1,287.31 : x
2. Step 2: Convert to fraction form
   2,930.75/4,395.90 = 1,287.31/x
3. Step 3: Cross multiply
   2,930.75x = 4,395.90 × 1,287.31
4. Step 4: Simplify right side
   2,930.75x = 5,658,879.59
5. Step 5: Solve for x
   x = 5,658,879.59/2,930.75
6. Step 6: Final answer
   x = 1,930.86