Finding the Fourth Proportional to 2,839.91, 4,260.56 and 991.05

Step by Step Solution

1. Step 1: Write the proportion equation
   2,839.91 : 4,260.56 = 991.05 : x
2. Step 2: Convert to fraction form
   2,839.91/4,260.56 = 991.05/x
3. Step 3: Cross multiply
   2,839.91x = 4,260.56 × 991.05
4. Step 4: Simplify right side
   2,839.91x = 4,222,406.69
5. Step 5: Solve for x
   x = 4,222,406.69/2,839.91
6. Step 6: Final answer
   x = 1,486.81