Finding the Fourth Proportional to 1,191.35, 1,644.04 and 667.40

Step by Step Solution

1. Step 1: Write the proportion equation
   1,191.35 : 1,644.04 = 667.40 : x
2. Step 2: Convert to fraction form
   1,191.35/1,644.04 = 667.40/x
3. Step 3: Cross multiply
   1,191.35x = 1,644.04 × 667.40
4. Step 4: Simplify right side
   1,191.35x = 1,097,232.30
5. Step 5: Solve for x
   x = 1,097,232.30/1,191.35
6. Step 6: Final answer
   x = 921.00