Finding the Fourth Proportional to 1,311.82, 1,967.92 and 763.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,311.82 : 1,967.92 = 763.72 : x
2. Step 2: Convert to fraction form
   1,311.82/1,967.92 = 763.72/x
3. Step 3: Cross multiply
   1,311.82x = 1,967.92 × 763.72
4. Step 4: Simplify right side
   1,311.82x = 1,502,939.86
5. Step 5: Solve for x
   x = 1,502,939.86/1,311.82
6. Step 6: Final answer
   x = 1,145.69