Finding the Fourth Proportional to 1,020.33, 1,520.82 and 989.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,020.33 : 1,520.82 = 989.55 : x
2. Step 2: Convert to fraction form
   1,020.33/1,520.82 = 989.55/x
3. Step 3: Cross multiply
   1,020.33x = 1,520.82 × 989.55
4. Step 4: Simplify right side
   1,020.33x = 1,504,927.43
5. Step 5: Solve for x
   x = 1,504,927.43/1,020.33
6. Step 6: Final answer
   x = 1,474.94