Finding the Fourth Proportional to 1,919.72, 2,880.06 and 765.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,919.72 : 2,880.06 = 765.56 : x
2. Step 2: Convert to fraction form
   1,919.72/2,880.06 = 765.56/x
3. Step 3: Cross multiply
   1,919.72x = 2,880.06 × 765.56
4. Step 4: Simplify right side
   1,919.72x = 2,204,858.73
5. Step 5: Solve for x
   x = 2,204,858.73/1,919.72
6. Step 6: Final answer
   x = 1,148.53