Finding the Fourth Proportional to 1,485.31, 2,228.61 and 791.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,485.31 : 2,228.61 = 791.78 : x
2. Step 2: Convert to fraction form
   1,485.31/2,228.61 = 791.78/x
3. Step 3: Cross multiply
   1,485.31x = 2,228.61 × 791.78
4. Step 4: Simplify right side
   1,485.31x = 1,764,568.83
5. Step 5: Solve for x
   x = 1,764,568.83/1,485.31
6. Step 6: Final answer
   x = 1,188.01