Finding the Fourth Proportional to 3,485.78, 5,229.31 and 1,145.91

Step by Step Solution

1. Step 1: Write the proportion equation
   3,485.78 : 5,229.31 = 1,145.91 : x
2. Step 2: Convert to fraction form
   3,485.78/5,229.31 = 1,145.91/x
3. Step 3: Cross multiply
   3,485.78x = 5,229.31 × 1,145.91
4. Step 4: Simplify right side
   3,485.78x = 5,992,318.62
5. Step 5: Solve for x
   x = 5,992,318.62/3,485.78
6. Step 6: Final answer
   x = 1,719.08