Finding the Fourth Proportional to 1,185.71, 1,636.34 and 661.70

Step by Step Solution

1. Step 1: Write the proportion equation
   1,185.71 : 1,636.34 = 661.70 : x
2. Step 2: Convert to fraction form
   1,185.71/1,636.34 = 661.70/x
3. Step 3: Cross multiply
   1,185.71x = 1,636.34 × 661.70
4. Step 4: Simplify right side
   1,185.71x = 1,082,766.96
5. Step 5: Solve for x
   x = 1,082,766.96/1,185.71
6. Step 6: Final answer
   x = 913.18