Finding the Fourth Proportional to 1,155.40, 1,728.78 and 880.52

Step by Step Solution

1. Step 1: Write the proportion equation
   1,155.40 : 1,728.78 = 880.52 : x
2. Step 2: Convert to fraction form
   1,155.40/1,728.78 = 880.52/x
3. Step 3: Cross multiply
   1,155.40x = 1,728.78 × 880.52
4. Step 4: Simplify right side
   1,155.40x = 1,522,225.37
5. Step 5: Solve for x
   x = 1,522,225.37/1,155.40
6. Step 6: Final answer
   x = 1,317.49