Finding the Fourth Proportional to 1,191.39, 1,644.14 and 667.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,191.39 : 1,644.14 = 667.42 : x
2. Step 2: Convert to fraction form
   1,191.39/1,644.14 = 667.42/x
3. Step 3: Cross multiply
   1,191.39x = 1,644.14 × 667.42
4. Step 4: Simplify right side
   1,191.39x = 1,097,331.92
5. Step 5: Solve for x
   x = 1,097,331.92/1,191.39
6. Step 6: Final answer
   x = 921.05