Finding the Fourth Proportional to 2,639.59, 3,959.58 and 1,178.89

Step by Step Solution

1. Step 1: Write the proportion equation
   2,639.59 : 3,959.58 = 1,178.89 : x
2. Step 2: Convert to fraction form
   2,639.59/3,959.58 = 1,178.89/x
3. Step 3: Cross multiply
   2,639.59x = 3,959.58 × 1,178.89
4. Step 4: Simplify right side
   2,639.59x = 4,667,903.79
5. Step 5: Solve for x
   x = 4,667,903.79/2,639.59
6. Step 6: Final answer
   x = 1,768.42