Finding the Fourth Proportional to 1,191.59, 1,644.39 and 660.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,191.59 : 1,644.39 = 660.50 : x
2. Step 2: Convert to fraction form
   1,191.59/1,644.39 = 660.50/x
3. Step 3: Cross multiply
   1,191.59x = 1,644.39 × 660.50
4. Step 4: Simplify right side
   1,191.59x = 1,086,111.37
5. Step 5: Solve for x
   x = 1,086,111.37/1,191.59
6. Step 6: Final answer
   x = 911.48