Finding the Fourth Proportional to 2,092.72, 3,138.56 and 860.47

Step by Step Solution

1. Step 1: Write the proportion equation
   2,092.72 : 3,138.56 = 860.47 : x
2. Step 2: Convert to fraction form
   2,092.72/3,138.56 = 860.47/x
3. Step 3: Cross multiply
   2,092.72x = 3,138.56 × 860.47
4. Step 4: Simplify right side
   2,092.72x = 2,700,636.72
5. Step 5: Solve for x
   x = 2,700,636.72/2,092.72
6. Step 6: Final answer
   x = 1,290.49