Finding the Fourth Proportional to 1,311.42, 1,967.55 and 661.95

Step by Step Solution

1. Step 1: Write the proportion equation
   1,311.42 : 1,967.55 = 661.95 : x
2. Step 2: Convert to fraction form
   1,311.42/1,967.55 = 661.95/x
3. Step 3: Cross multiply
   1,311.42x = 1,967.55 × 661.95
4. Step 4: Simplify right side
   1,311.42x = 1,302,419.72
5. Step 5: Solve for x
   x = 1,302,419.72/1,311.42
6. Step 6: Final answer
   x = 993.14