Finding the Fourth Proportional to 1,161.98, 1,603.56 and 664.77

Step by Step Solution

1. Step 1: Write the proportion equation
   1,161.98 : 1,603.56 = 664.77 : x
2. Step 2: Convert to fraction form
   1,161.98/1,603.56 = 664.77/x
3. Step 3: Cross multiply
   1,161.98x = 1,603.56 × 664.77
4. Step 4: Simplify right side
   1,161.98x = 1,066,007.09
5. Step 5: Solve for x
   x = 1,066,007.09/1,161.98
6. Step 6: Final answer
   x = 917.41