Finding the Fourth Proportional to 1,012.78, 1,519.12 and 282.34

Step by Step Solution

1. Step 1: Write the proportion equation
   1,012.78 : 1,519.12 = 282.34 : x
2. Step 2: Convert to fraction form
   1,012.78/1,519.12 = 282.34/x
3. Step 3: Cross multiply
   1,012.78x = 1,519.12 × 282.34
4. Step 4: Simplify right side
   1,012.78x = 428,908.34
5. Step 5: Solve for x
   x = 428,908.34/1,012.78
6. Step 6: Final answer
   x = 423.50