Finding the Fourth Proportional to 1,640.25, 2,461.59 and 774.77

Step by Step Solution

1. Step 1: Write the proportion equation
   1,640.25 : 2,461.59 = 774.77 : x
2. Step 2: Convert to fraction form
   1,640.25/2,461.59 = 774.77/x
3. Step 3: Cross multiply
   1,640.25x = 2,461.59 × 774.77
4. Step 4: Simplify right side
   1,640.25x = 1,907,153.78
5. Step 5: Solve for x
   x = 1,907,153.78/1,640.25
6. Step 6: Final answer
   x = 1,162.72