Finding the Fourth Proportional to 3,665.10, 5,057.78 and 1,986.47

Step by Step Solution

1. Step 1: Write the proportion equation
   3,665.10 : 5,057.78 = 1,986.47 : x
2. Step 2: Convert to fraction form
   3,665.10/5,057.78 = 1,986.47/x
3. Step 3: Cross multiply
   3,665.10x = 5,057.78 × 1,986.47
4. Step 4: Simplify right side
   3,665.10x = 10,047,093.02
5. Step 5: Solve for x
   x = 10,047,093.02/3,665.10
6. Step 6: Final answer
   x = 2,741.29