Finding the Fourth Proportional to 1,435.20, 1,980.56 and 1,085.28

Step by Step Solution

1. Step 1: Write the proportion equation
   1,435.20 : 1,980.56 = 1,085.28 : x
2. Step 2: Convert to fraction form
   1,435.20/1,980.56 = 1,085.28/x
3. Step 3: Cross multiply
   1,435.20x = 1,980.56 × 1,085.28
4. Step 4: Simplify right side
   1,435.20x = 2,149,462.16
5. Step 5: Solve for x
   x = 2,149,462.16/1,435.20
6. Step 6: Final answer
   x = 1,497.67