Finding the Fourth Proportional to 1,109.50, 1,531.09 and 667.64

Step by Step Solution

1. Step 1: Write the proportion equation
   1,109.50 : 1,531.09 = 667.64 : x
2. Step 2: Convert to fraction form
   1,109.50/1,531.09 = 667.64/x
3. Step 3: Cross multiply
   1,109.50x = 1,531.09 × 667.64
4. Step 4: Simplify right side
   1,109.50x = 1,022,216.93
5. Step 5: Solve for x
   x = 1,022,216.93/1,109.50
6. Step 6: Final answer
   x = 921.33