Finding the Fourth Proportional to 1,191.21, 1,643.94 and 667.32

Step by Step Solution

1. Step 1: Write the proportion equation
   1,191.21 : 1,643.94 = 667.32 : x
2. Step 2: Convert to fraction form
   1,191.21/1,643.94 = 667.32/x
3. Step 3: Cross multiply
   1,191.21x = 1,643.94 × 667.32
4. Step 4: Simplify right side
   1,191.21x = 1,097,034.04
5. Step 5: Solve for x
   x = 1,097,034.04/1,191.21
6. Step 6: Final answer
   x = 920.94