Finding the Fourth Proportional to 1,185.78, 1,777.86 and 665.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,185.78 : 1,777.86 = 665.82 : x
2. Step 2: Convert to fraction form
   1,185.78/1,777.86 = 665.82/x
3. Step 3: Cross multiply
   1,185.78x = 1,777.86 × 665.82
4. Step 4: Simplify right side
   1,185.78x = 1,183,734.75
5. Step 5: Solve for x
   x = 1,183,734.75/1,185.78
6. Step 6: Final answer
   x = 998.28