Finding the Fourth Proportional to 1,023.40, 1,413.72 and 912.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,023.40 : 1,413.72 = 912.82 : x
2. Step 2: Convert to fraction form
   1,023.40/1,413.72 = 912.82/x
3. Step 3: Cross multiply
   1,023.40x = 1,413.72 × 912.82
4. Step 4: Simplify right side
   1,023.40x = 1,290,471.89
5. Step 5: Solve for x
   x = 1,290,471.89/1,023.40
6. Step 6: Final answer
   x = 1,260.97