Finding the Fourth Proportional to 1,185.76, 1,636.38 and 661.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,185.76 : 1,636.38 = 661.78 : x
2. Step 2: Convert to fraction form
   1,185.76/1,636.38 = 661.78/x
3. Step 3: Cross multiply
   1,185.76x = 1,636.38 × 661.78
4. Step 4: Simplify right side
   1,185.76x = 1,082,923.56
5. Step 5: Solve for x
   x = 1,082,923.56/1,185.76
6. Step 6: Final answer
   x = 913.27