Finding the Fourth Proportional to 1,315.92, 1,815.72 and 791.76

Step by Step Solution

1. Step 1: Write the proportion equation
   1,315.92 : 1,815.72 = 791.76 : x
2. Step 2: Convert to fraction form
   1,315.92/1,815.72 = 791.76/x
3. Step 3: Cross multiply
   1,315.92x = 1,815.72 × 791.76
4. Step 4: Simplify right side
   1,315.92x = 1,437,614.47
5. Step 5: Solve for x
   x = 1,437,614.47/1,315.92
6. Step 6: Final answer
   x = 1,092.48