Finding the Fourth Proportional to 1,012.40, 1,509.94 and 908.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,012.40 : 1,509.94 = 908.72 : x
2. Step 2: Convert to fraction form
   1,012.40/1,509.94 = 908.72/x
3. Step 3: Cross multiply
   1,012.40x = 1,509.94 × 908.72
4. Step 4: Simplify right side
   1,012.40x = 1,372,112.68
5. Step 5: Solve for x
   x = 1,372,112.68/1,012.40
6. Step 6: Final answer
   x = 1,355.31