Finding the Fourth Proportional to 1,219.80, 1,683.33 and 660.27

Step by Step Solution

1. Step 1: Write the proportion equation
   1,219.80 : 1,683.33 = 660.27 : x
2. Step 2: Convert to fraction form
   1,219.80/1,683.33 = 660.27/x
3. Step 3: Cross multiply
   1,219.80x = 1,683.33 × 660.27
4. Step 4: Simplify right side
   1,219.80x = 1,111,444.79
5. Step 5: Solve for x
   x = 1,111,444.79/1,219.80
6. Step 6: Final answer
   x = 911.17