Finding the Fourth Proportional to 2,086.65, 3,128.16 and 1,045.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,086.65 : 3,128.16 = 1,045.20 : x
2. Step 2: Convert to fraction form
   2,086.65/3,128.16 = 1,045.20/x
3. Step 3: Cross multiply
   2,086.65x = 3,128.16 × 1,045.20
4. Step 4: Simplify right side
   2,086.65x = 3,269,537.18
5. Step 5: Solve for x
   x = 3,269,537.18/2,086.65
6. Step 6: Final answer
   x = 1,566.88