Finding the Fourth Proportional to 1,311.86, 1,968.96 and 1,172.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,311.86 : 1,968.96 = 1,172.82 : x
2. Step 2: Convert to fraction form
   1,311.86/1,968.96 = 1,172.82/x
3. Step 3: Cross multiply
   1,311.86x = 1,968.96 × 1,172.82
4. Step 4: Simplify right side
   1,311.86x = 2,309,235.67
5. Step 5: Solve for x
   x = 2,309,235.67/1,311.86
6. Step 6: Final answer
   x = 1,760.28