Finding the Fourth Proportional to 1,165.91, 1,608.59 and 661.68

Step by Step Solution

1. Step 1: Write the proportion equation
   1,165.91 : 1,608.59 = 661.68 : x
2. Step 2: Convert to fraction form
   1,165.91/1,608.59 = 661.68/x
3. Step 3: Cross multiply
   1,165.91x = 1,608.59 × 661.68
4. Step 4: Simplify right side
   1,165.91x = 1,064,367.81
5. Step 5: Solve for x
   x = 1,064,367.81/1,165.91
6. Step 6: Final answer
   x = 912.91