Finding the Fourth Proportional to 2,665.89, 3,680.51 and 1,921.77

Step by Step Solution

1. Step 1: Write the proportion equation
   2,665.89 : 3,680.51 = 1,921.77 : x
2. Step 2: Convert to fraction form
   2,665.89/3,680.51 = 1,921.77/x
3. Step 3: Cross multiply
   2,665.89x = 3,680.51 × 1,921.77
4. Step 4: Simplify right side
   2,665.89x = 7,073,084.09
5. Step 5: Solve for x
   x = 7,073,084.09/2,665.89
6. Step 6: Final answer
   x = 2,653.18