Finding the Fourth Proportional to 1,509.72, 2,083.50 and 920.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,509.72 : 2,083.50 = 920.31 : x
2. Step 2: Convert to fraction form
   1,509.72/2,083.50 = 920.31/x
3. Step 3: Cross multiply
   1,509.72x = 2,083.50 × 920.31
4. Step 4: Simplify right side
   1,509.72x = 1,917,465.89
5. Step 5: Solve for x
   x = 1,917,465.89/1,509.72
6. Step 6: Final answer
   x = 1,270.08