Finding the Fourth Proportional to 1,111.68, 1,665.60 and 819.36

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.68 : 1,665.60 = 819.36 : x
2. Step 2: Convert to fraction form
   1,111.68/1,665.60 = 819.36/x
3. Step 3: Cross multiply
   1,111.68x = 1,665.60 × 819.36
4. Step 4: Simplify right side
   1,111.68x = 1,364,726.02
5. Step 5: Solve for x
   x = 1,364,726.02/1,111.68
6. Step 6: Final answer
   x = 1,227.62