Finding the Fourth Proportional to 1,219.69, 1,683.17 and 660.16

Step by Step Solution

1. Step 1: Write the proportion equation
   1,219.69 : 1,683.17 = 660.16 : x
2. Step 2: Convert to fraction form
   1,219.69/1,683.17 = 660.16/x
3. Step 3: Cross multiply
   1,219.69x = 1,683.17 × 660.16
4. Step 4: Simplify right side
   1,219.69x = 1,111,171.23
5. Step 5: Solve for x
   x = 1,111,171.23/1,219.69
6. Step 6: Final answer
   x = 911.03