Finding the Fourth Proportional to 1,105.49, 1,659.40 and 667.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,105.49 : 1,659.40 = 667.80 : x
2. Step 2: Convert to fraction form
   1,105.49/1,659.40 = 667.80/x
3. Step 3: Cross multiply
   1,105.49x = 1,659.40 × 667.80
4. Step 4: Simplify right side
   1,105.49x = 1,108,145.65
5. Step 5: Solve for x
   x = 1,108,145.65/1,105.49
6. Step 6: Final answer
   x = 1,002.40