Finding the Fourth Proportional to 1,075.69, 1,610.61 and 855.28

Step by Step Solution

1. Step 1: Write the proportion equation
   1,075.69 : 1,610.61 = 855.28 : x
2. Step 2: Convert to fraction form
   1,075.69/1,610.61 = 855.28/x
3. Step 3: Cross multiply
   1,075.69x = 1,610.61 × 855.28
4. Step 4: Simplify right side
   1,075.69x = 1,377,522.52
5. Step 5: Solve for x
   x = 1,377,522.52/1,075.69
6. Step 6: Final answer
   x = 1,280.59