Finding the Fourth Proportional to 2,118.72, 3,178.39 and 731.68

Step by Step Solution

1. Step 1: Write the proportion equation
   2,118.72 : 3,178.39 = 731.68 : x
2. Step 2: Convert to fraction form
   2,118.72/3,178.39 = 731.68/x
3. Step 3: Cross multiply
   2,118.72x = 3,178.39 × 731.68
4. Step 4: Simplify right side
   2,118.72x = 2,325,562.87
5. Step 5: Solve for x
   x = 2,325,562.87/2,118.72
6. Step 6: Final answer
   x = 1,097.63