Finding the Fourth Proportional to 3,919.74, 5,879.69 and 1,287.37

Step by Step Solution

1. Step 1: Write the proportion equation
   3,919.74 : 5,879.69 = 1,287.37 : x
2. Step 2: Convert to fraction form
   3,919.74/5,879.69 = 1,287.37/x
3. Step 3: Cross multiply
   3,919.74x = 5,879.69 × 1,287.37
4. Step 4: Simplify right side
   3,919.74x = 7,569,325.72
5. Step 5: Solve for x
   x = 7,569,325.72/3,919.74
6. Step 6: Final answer
   x = 1,931.08