Finding the Fourth Proportional to 2,629.05, 3,928.31 and 1,991.58

Step by Step Solution

1. Step 1: Write the proportion equation
   2,629.05 : 3,928.31 = 1,991.58 : x
2. Step 2: Convert to fraction form
   2,629.05/3,928.31 = 1,991.58/x
3. Step 3: Cross multiply
   2,629.05x = 3,928.31 × 1,991.58
4. Step 4: Simplify right side
   2,629.05x = 7,823,543.63
5. Step 5: Solve for x
   x = 7,823,543.63/2,629.05
6. Step 6: Final answer
   x = 2,975.81