Finding the Fourth Proportional to 1,165.39, 1,608.12 and 667.91

Step by Step Solution

1. Step 1: Write the proportion equation
   1,165.39 : 1,608.12 = 667.91 : x
2. Step 2: Convert to fraction form
   1,165.39/1,608.12 = 667.91/x
3. Step 3: Cross multiply
   1,165.39x = 1,608.12 × 667.91
4. Step 4: Simplify right side
   1,165.39x = 1,074,083.45
5. Step 5: Solve for x
   x = 1,074,083.45/1,165.39
6. Step 6: Final answer
   x = 921.65