Finding the Fourth Proportional to 1,191.27, 1,643.88 and 660.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,191.27 : 1,643.88 = 660.12 : x
2. Step 2: Convert to fraction form
   1,191.27/1,643.88 = 660.12/x
3. Step 3: Cross multiply
   1,191.27x = 1,643.88 × 660.12
4. Step 4: Simplify right side
   1,191.27x = 1,085,158.07
5. Step 5: Solve for x
   x = 1,085,158.07/1,191.27
6. Step 6: Final answer
   x = 910.93