Finding the Fourth Proportional to 1,386.24, 1,912.97 and 788.73

Step by Step Solution

1. Step 1: Write the proportion equation
   1,386.24 : 1,912.97 = 788.73 : x
2. Step 2: Convert to fraction form
   1,386.24/1,912.97 = 788.73/x
3. Step 3: Cross multiply
   1,386.24x = 1,912.97 × 788.73
4. Step 4: Simplify right side
   1,386.24x = 1,508,816.83
5. Step 5: Solve for x
   x = 1,508,816.83/1,386.24
6. Step 6: Final answer
   x = 1,088.42