Finding the Fourth Proportional to 3,986.60, 5,978.52 and 1,908.95

Step by Step Solution

1. Step 1: Write the proportion equation
   3,986.60 : 5,978.52 = 1,908.95 : x
2. Step 2: Convert to fraction form
   3,986.60/5,978.52 = 1,908.95/x
3. Step 3: Cross multiply
   3,986.60x = 5,978.52 × 1,908.95
4. Step 4: Simplify right side
   3,986.60x = 11,412,665.86
5. Step 5: Solve for x
   x = 11,412,665.86/3,986.60
6. Step 6: Final answer
   x = 2,862.76