Finding the Fourth Proportional to 1,289.72, 1,931.52 and 819.51

Step by Step Solution

1. Step 1: Write the proportion equation
   1,289.72 : 1,931.52 = 819.51 : x
2. Step 2: Convert to fraction form
   1,289.72/1,931.52 = 819.51/x
3. Step 3: Cross multiply
   1,289.72x = 1,931.52 × 819.51
4. Step 4: Simplify right side
   1,289.72x = 1,582,895.79
5. Step 5: Solve for x
   x = 1,582,895.79/1,289.72
6. Step 6: Final answer
   x = 1,227.32