Finding the Fourth Proportional to 1,775.18, 2,665.20 and 1,128.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,775.18 : 2,665.20 = 1,128.80 : x
2. Step 2: Convert to fraction form
   1,775.18/2,665.20 = 1,128.80/x
3. Step 3: Cross multiply
   1,775.18x = 2,665.20 × 1,128.80
4. Step 4: Simplify right side
   1,775.18x = 3,008,477.76
5. Step 5: Solve for x
   x = 3,008,477.76/1,775.18
6. Step 6: Final answer
   x = 1,694.75