Finding the Fourth Proportional to 1,022.12, 1,409.77 and 648.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,022.12 : 1,409.77 = 648.78 : x
2. Step 2: Convert to fraction form
   1,022.12/1,409.77 = 648.78/x
3. Step 3: Cross multiply
   1,022.12x = 1,409.77 × 648.78
4. Step 4: Simplify right side
   1,022.12x = 914,620.29
5. Step 5: Solve for x
   x = 914,620.29/1,022.12
6. Step 6: Final answer
   x = 894.83