Finding the Fourth Proportional to 1,238.53, 1,709.56 and 819.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,238.53 : 1,709.56 = 819.15 : x
2. Step 2: Convert to fraction form
   1,238.53/1,709.56 = 819.15/x
3. Step 3: Cross multiply
   1,238.53x = 1,709.56 × 819.15
4. Step 4: Simplify right side
   1,238.53x = 1,400,388.12
5. Step 5: Solve for x
   x = 1,400,388.12/1,238.53
6. Step 6: Final answer
   x = 1,130.69