Finding the Fourth Proportional to 2,640.87, 3,961.98 and 792.63

Step by Step Solution

1. Step 1: Write the proportion equation
   2,640.87 : 3,961.98 = 792.63 : x
2. Step 2: Convert to fraction form
   2,640.87/3,961.98 = 792.63/x
3. Step 3: Cross multiply
   2,640.87x = 3,961.98 × 792.63
4. Step 4: Simplify right side
   2,640.87x = 3,140,384.21
5. Step 5: Solve for x
   x = 3,140,384.21/2,640.87
6. Step 6: Final answer
   x = 1,189.15