Finding the Fourth Proportional to 1,191.32, 1,644.12 and 667.28

Step by Step Solution

1. Step 1: Write the proportion equation
   1,191.32 : 1,644.12 = 667.28 : x
2. Step 2: Convert to fraction form
   1,191.32/1,644.12 = 667.28/x
3. Step 3: Cross multiply
   1,191.32x = 1,644.12 × 667.28
4. Step 4: Simplify right side
   1,191.32x = 1,097,088.39
5. Step 5: Solve for x
   x = 1,097,088.39/1,191.32
6. Step 6: Final answer
   x = 920.90