Finding the Fourth Proportional to 1,191.29, 1,643.96 and 667.43

Step by Step Solution

1. Step 1: Write the proportion equation
   1,191.29 : 1,643.96 = 667.43 : x
2. Step 2: Convert to fraction form
   1,191.29/1,643.96 = 667.43/x
3. Step 3: Cross multiply
   1,191.29x = 1,643.96 × 667.43
4. Step 4: Simplify right side
   1,191.29x = 1,097,221.67
5. Step 5: Solve for x
   x = 1,097,221.67/1,191.29
6. Step 6: Final answer
   x = 921.03