Finding the Fourth Proportional to 2,647.92, 3,972.68 and 916.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,647.92 : 3,972.68 = 916.72 : x
2. Step 2: Convert to fraction form
   2,647.92/3,972.68 = 916.72/x
3. Step 3: Cross multiply
   2,647.92x = 3,972.68 × 916.72
4. Step 4: Simplify right side
   2,647.92x = 3,641,835.21
5. Step 5: Solve for x
   x = 3,641,835.21/2,647.92
6. Step 6: Final answer
   x = 1,375.36