Finding the Fourth Proportional to 1,137.69, 1,570.19 and 783.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,137.69 : 1,570.19 = 783.31 : x
2. Step 2: Convert to fraction form
   1,137.69/1,570.19 = 783.31/x
3. Step 3: Cross multiply
   1,137.69x = 1,570.19 × 783.31
4. Step 4: Simplify right side
   1,137.69x = 1,229,945.53
5. Step 5: Solve for x
   x = 1,229,945.53/1,137.69
6. Step 6: Final answer
   x = 1,081.09