Finding the Fourth Proportional to 2,651.89, 3,977.88 and 920.55

Step by Step Solution

1. Step 1: Write the proportion equation
   2,651.89 : 3,977.88 = 920.55 : x
2. Step 2: Convert to fraction form
   2,651.89/3,977.88 = 920.55/x
3. Step 3: Cross multiply
   2,651.89x = 3,977.88 × 920.55
4. Step 4: Simplify right side
   2,651.89x = 3,661,837.43
5. Step 5: Solve for x
   x = 3,661,837.43/2,651.89
6. Step 6: Final answer
   x = 1,380.84