Finding the Fourth Proportional to 1,089.30, 1,635.15 and 1,018.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,089.30 : 1,635.15 = 1,018.80 : x
2. Step 2: Convert to fraction form
   1,089.30/1,635.15 = 1,018.80/x
3. Step 3: Cross multiply
   1,089.30x = 1,635.15 × 1,018.80
4. Step 4: Simplify right side
   1,089.30x = 1,665,890.82
5. Step 5: Solve for x
   x = 1,665,890.82/1,089.30
6. Step 6: Final answer
   x = 1,529.32