Finding the Fourth Proportional to 1,191.59, 1,644.41 and 667.79

Step by Step Solution

1. Step 1: Write the proportion equation
   1,191.59 : 1,644.41 = 667.79 : x
2. Step 2: Convert to fraction form
   1,191.59/1,644.41 = 667.79/x
3. Step 3: Cross multiply
   1,191.59x = 1,644.41 × 667.79
4. Step 4: Simplify right side
   1,191.59x = 1,098,120.55
5. Step 5: Solve for x
   x = 1,098,120.55/1,191.59
6. Step 6: Final answer
   x = 921.56