Finding the Fourth Proportional to 1,191.53, 1,644.29 and 667.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,191.53 : 1,644.29 = 667.55 : x
2. Step 2: Convert to fraction form
   1,191.53/1,644.29 = 667.55/x
3. Step 3: Cross multiply
   1,191.53x = 1,644.29 × 667.55
4. Step 4: Simplify right side
   1,191.53x = 1,097,634.23
5. Step 5: Solve for x
   x = 1,097,634.23/1,191.53
6. Step 6: Final answer
   x = 921.20