Finding the Fourth Proportional to 1,920.72, 2,880.16 and 766.16

Step by Step Solution

1. Step 1: Write the proportion equation
   1,920.72 : 2,880.16 = 766.16 : x
2. Step 2: Convert to fraction form
   1,920.72/2,880.16 = 766.16/x
3. Step 3: Cross multiply
   1,920.72x = 2,880.16 × 766.16
4. Step 4: Simplify right side
   1,920.72x = 2,206,663.39
5. Step 5: Solve for x
   x = 2,206,663.39/1,920.72
6. Step 6: Final answer
   x = 1,148.87